diff --git a/Numscript.g4 b/Numscript.g4
index 793d2d9..4ea640b 100644
--- a/Numscript.g4
+++ b/Numscript.g4
@@ -60,7 +60,8 @@ valueExpr:
 	| left = valueExpr op = ('+' | '-') right = valueExpr	# infixExpr;
 
 functionCallArgs: valueExpr ( COMMA valueExpr)*;
-functionCall: IDENTIFIER LPARENS functionCallArgs? RPARENS;
+functionCall:
+	fnName = (OVERDRAFT | IDENTIFIER) LPARENS functionCallArgs? RPARENS;
 
 varOrigin: EQ functionCall;
 varDeclaration:
diff --git a/internal/analysis/check.go b/internal/analysis/check.go
index 38ef771..eeb4717 100644
--- a/internal/analysis/check.go
+++ b/internal/analysis/check.go
@@ -55,6 +55,7 @@ const FnSetTxMeta = "set_tx_meta"
 const FnSetAccountMeta = "set_account_meta"
 const FnVarOriginMeta = "meta"
 const FnVarOriginBalance = "balance"
+const FnVarOriginOverdraft = "overdraft"
 
 var Builtins = map[string]FnCallResolution{
 	FnSetTxMeta: StatementFnCallResolution{
@@ -75,6 +76,11 @@ var Builtins = map[string]FnCallResolution{
 		Return: TypeMonetary,
 		Docs:   "fetch account balance",
 	},
+	FnVarOriginOverdraft: VarOriginFnCallResolution{
+		Params: []string{TypeAccount, TypeAsset},
+		Return: TypeMonetary,
+		Docs:   "get absolute amount of the overdraft of an account. Returns zero if balance is not negative",
+	},
 }
 
 type Diagnostic struct {
diff --git a/internal/cmd/run.go b/internal/cmd/run.go
index b4f52b4..d7ba612 100644
--- a/internal/cmd/run.go
+++ b/internal/cmd/run.go
@@ -26,6 +26,8 @@ var runRawOpt string
 var runStdinFlag bool
 var runOutFormatOpt string
 
+var overdraftFeatureFlag bool
+
 type inputOpts struct {
 	Script    string                       `json:"script"`
 	Variables map[string]string            `json:"variables"`
@@ -115,10 +117,15 @@ func run(path string) {
 		os.Exit(1)
 	}
 
+	featureFlags := map[string]struct{}{}
+	if overdraftFeatureFlag {
+		featureFlags[interpreter.ExperimentalOverdraftFunctionFeatureFlag] = struct{}{}
+	}
+
 	result, err := interpreter.RunProgram(context.Background(), parseResult.Value, opt.Variables, interpreter.StaticStore{
 		Balances: opt.Balances,
 		Meta:     opt.Meta,
-	}, nil)
+	}, featureFlags)
 
 	if err != nil {
 		rng := err.GetRange()
@@ -192,6 +199,9 @@ func getRunCmd() *cobra.Command {
 	cmd.Flags().StringVarP(&runRawOpt, "raw", "r", "", "Raw json input containing script, variables, balances, metadata")
 	cmd.Flags().BoolVar(&runStdinFlag, "stdin", false, "Take input from stdin (same format as the --raw option)")
 
+	// Feature flag
+	cmd.Flags().BoolVar(&overdraftFeatureFlag, interpreter.ExperimentalOverdraftFunctionFeatureFlag, false, "feature flag to enable the overdraft() function")
+
 	// Output options
 	cmd.Flags().StringVar(&runOutFormatOpt, "output-format", OutputFormatPretty, "Set the output format. Available options: pretty, json.")
 
diff --git a/internal/interpreter/interpreter.go b/internal/interpreter/interpreter.go
index 989b303..78382a4 100644
--- a/internal/interpreter/interpreter.go
+++ b/internal/interpreter/interpreter.go
@@ -140,6 +140,13 @@ func (s *programState) handleOrigin(type_ string, fnCall parser.FnCall) (Value,
 		}
 		return *monetary, nil
 
+	case analysis.FnVarOriginOverdraft:
+		monetary, err := overdraft(s, fnCall.Range, args)
+		if err != nil {
+			return nil, err
+		}
+		return *monetary, nil
+
 	default:
 		return nil, UnboundFunctionErr{Name: fnCall.Caller.Name}
 	}
@@ -170,6 +177,10 @@ func (s *programState) parseVars(varDeclrs []parser.VarDeclaration, rawVars map[
 	return nil
 }
 
+type FeatureFlag = string
+
+const ExperimentalOverdraftFunctionFeatureFlag FeatureFlag = "experimental-overdraft-function"
+
 func RunProgram(
 	ctx context.Context,
 	program parser.Program,
@@ -189,6 +200,10 @@ func RunProgram(
 		ctx:                 ctx,
 	}
 
+	if _, ok := featureFlags[ExperimentalOverdraftFunctionFeatureFlag]; ok {
+		st.OverdraftFunctionFeatureFlag = true
+	}
+
 	err := st.parseVars(program.Vars, vars)
 	if err != nil {
 		return nil, err
@@ -245,6 +260,8 @@ type programState struct {
 	CachedBalances     Balances
 
 	CurrentBalanceQuery BalanceQuery
+
+	OverdraftFunctionFeatureFlag bool
 }
 
 func (st *programState) pushSender(name string, monetary *big.Int) {
@@ -778,6 +795,22 @@ func meta(
 	return value, nil
 }
 
+// Utility function to get the balance
+func getBalance(
+	s *programState,
+	account string,
+	asset string,
+) (*big.Int, InterpreterError) {
+	s.batchQuery(account, asset)
+	fetchBalanceErr := s.runBalancesQuery()
+	if fetchBalanceErr != nil {
+		return nil, QueryBalanceError{WrappedError: fetchBalanceErr}
+	}
+	balance := s.getCachedBalance(account, asset)
+	return balance, nil
+
+}
+
 func balance(
 	s *programState,
 	r parser.Range,
@@ -793,13 +826,12 @@ func balance(
 	}
 
 	// body
-	s.batchQuery(*account, *asset)
-	fetchBalanceErr := s.runBalancesQuery()
-	if fetchBalanceErr != nil {
-		return nil, QueryBalanceError{WrappedError: fetchBalanceErr}
+
+	balance, err := getBalance(s, *account, *asset)
+	if err != nil {
+		return nil, err
 	}
 
-	balance := s.getCachedBalance(*account, *asset)
 	if balance.Cmp(big.NewInt(0)) == -1 {
 		return nil, NegativeBalanceError{
 			Account: *account,
@@ -816,6 +848,44 @@ func balance(
 	return &m, nil
 }
 
+func overdraft(
+	s *programState,
+	r parser.Range,
+	args []Value,
+) (*Monetary, InterpreterError) {
+	if !s.OverdraftFunctionFeatureFlag {
+		return nil, ExperimentalFeature{FlagName: ExperimentalOverdraftFunctionFeatureFlag}
+	}
+
+	// TODO more precise args range location
+	p := NewArgsParser(args)
+	account := parseArg(p, r, expectAccount)
+	asset := parseArg(p, r, expectAsset)
+	err := p.parse()
+	if err != nil {
+		return nil, err
+	}
+
+	balance_, err := getBalance(s, *account, *asset)
+	if err != nil {
+		return nil, err
+	}
+
+	balanceIsPositive := balance_.Cmp(big.NewInt(0)) == 1
+	if balanceIsPositive {
+		return &Monetary{
+			Amount: NewMonetaryInt(0),
+			Asset:  Asset(*asset),
+		}, nil
+	}
+
+	overdraft := new(big.Int).Neg(balance_)
+	return &Monetary{
+		Amount: MonetaryInt(*overdraft),
+		Asset:  Asset(*asset),
+	}, nil
+}
+
 func setTxMeta(st *programState, r parser.Range, args []Value) InterpreterError {
 	p := NewArgsParser(args)
 	key := parseArg(p, r, expectString)
diff --git a/internal/interpreter/interpreter_error.go b/internal/interpreter/interpreter_error.go
index 168df11..c819f1a 100644
--- a/internal/interpreter/interpreter_error.go
+++ b/internal/interpreter/interpreter_error.go
@@ -184,3 +184,12 @@ type QueryMetadataError struct {
 func (e QueryMetadataError) Error() string {
 	return e.WrappedError.Error()
 }
+
+type ExperimentalFeature struct {
+	parser.Range
+	FlagName string
+}
+
+func (e ExperimentalFeature) Error() string {
+	return fmt.Sprintf("this feature is experimental. You need the '%s' feature flag to enable it", e.FlagName)
+}
diff --git a/internal/interpreter/interpreter_test.go b/internal/interpreter/interpreter_test.go
index 7d068dc..8a200fb 100644
--- a/internal/interpreter/interpreter_test.go
+++ b/internal/interpreter/interpreter_test.go
@@ -82,16 +82,50 @@ func (c *TestCase) setBalance(account string, asset string, amount int64) {
 }
 
 func test(t *testing.T, testCase TestCase) {
+	testWithFeatureFlag(t, testCase, "")
+}
+
+// A version of test() which tests code under a feature flag
+// if the feature flag is the empty string, it behaves as test()
+// otherwise, it tests the program under that feature flag and also tests that
+// the same script, without the flag, yields the ExperimentalFeature{} error
+func testWithFeatureFlag(t *testing.T, testCase TestCase, flagName string) {
 	t.Parallel()
 
 	prog := testCase.program
 
 	require.NotNil(t, prog)
 
-	execResult, err := machine.RunProgram(context.Background(), *prog, testCase.vars, machine.StaticStore{
-		testCase.balances,
-		testCase.meta,
-	}, nil)
+	featureFlags := map[string]struct{}{}
+	if flagName != "" {
+		featureFlags[flagName] = struct{}{}
+
+		_, err := machine.RunProgram(
+			context.Background(),
+			*prog,
+			testCase.vars,
+			machine.StaticStore{
+				testCase.balances,
+				testCase.meta,
+			},
+			nil,
+		)
+
+		require.Equal(t, machine.ExperimentalFeature{
+			FlagName: flagName,
+		}, removeRange(err))
+	}
+
+	execResult, err := machine.RunProgram(
+		context.Background(),
+		*prog,
+		testCase.vars,
+		machine.StaticStore{
+			testCase.balances,
+			testCase.meta,
+		},
+		featureFlags,
+	)
 
 	expected := testCase.expected
 	if expected.Error != nil {
@@ -3266,6 +3300,117 @@ func TestSaveFromAccount(t *testing.T) {
 	})
 }
 
+func TestOverdraftFunctionWhenNegative(t *testing.T) {
+	script := `
+ 		vars { monetary $amt = overdraft(@acc, EUR/2) }
+
+ 		send $amt (
+ 			source = @world
+ 			destination = @dest
+ 		)
+
+	`
+
+	tc := NewTestCase()
+	tc.compile(t, script)
+
+	tc.setBalance("acc", "EUR/2", -100)
+	tc.expected = CaseResult{
+		Postings: []Posting{
+			{
+				Asset:       "EUR/2",
+				Amount:      big.NewInt(100),
+				Source:      "world",
+				Destination: "dest",
+			},
+		},
+		Error: nil,
+	}
+	testWithFeatureFlag(t, tc, machine.ExperimentalOverdraftFunctionFeatureFlag)
+}
+
+func TestOverdraftFunctionWhenZero(t *testing.T) {
+	script := `
+ 		vars { monetary $amt = overdraft(@acc, EUR/2) }
+
+ 		send $amt (
+ 			source = @world
+ 			destination = @dest
+ 		)
+
+	`
+
+	tc := NewTestCase()
+	tc.compile(t, script)
+
+	tc.expected = CaseResult{
+		Postings: []Posting{
+			// zero posting is omitted
+		},
+		Error: nil,
+	}
+	testWithFeatureFlag(t, tc, machine.ExperimentalOverdraftFunctionFeatureFlag)
+}
+
+func TestOverdraftFunctionWhenPositive(t *testing.T) {
+	script := `
+ 		vars { monetary $amt = overdraft(@acc, EUR/2) }
+
+ 		send $amt (
+ 			source = @world
+ 			destination = @dest
+ 		)
+	`
+
+	tc := NewTestCase()
+	tc.compile(t, script)
+
+	tc.setBalance("acc", "EUR/2", 100)
+
+	tc.expected = CaseResult{
+		Postings: []Posting{
+			// zero posting is omitted
+		},
+		Error: nil,
+	}
+	testWithFeatureFlag(t, tc, machine.ExperimentalOverdraftFunctionFeatureFlag)
+}
+
+func TestOverdraftFunctionUseCaseRemoveDebt(t *testing.T) {
+	script := `
+ 		vars { monetary $amt = overdraft(@user:001, USD/2) }
+
+
+		// we have at most 1000 USD/2 to remove user:001's debt
+ 		send [USD/2 1000] (
+ 			source = @world
+ 			destination = {
+				// but we send at most what we need to cancel the debt
+				max $amt to @user:001
+				remaining kept
+			}
+ 		)
+	`
+
+	tc := NewTestCase()
+	tc.compile(t, script)
+
+	tc.setBalance("user:001", "USD/2", -100)
+
+	tc.expected = CaseResult{
+		Postings: []Posting{
+			machine.Posting{
+				Asset:       "USD/2",
+				Amount:      big.NewInt(100),
+				Source:      "world",
+				Destination: "user:001",
+			},
+		},
+		Error: nil,
+	}
+	testWithFeatureFlag(t, tc, machine.ExperimentalOverdraftFunctionFeatureFlag)
+}
+
 func TestAddMonetariesSameCurrency(t *testing.T) {
 	script := `
  		send [COIN 1] + [COIN 2] (
diff --git a/internal/parser/antlr/Numscript.interp b/internal/parser/antlr/Numscript.interp
index 8dc2e94..56d0de5 100644
--- a/internal/parser/antlr/Numscript.interp
+++ b/internal/parser/antlr/Numscript.interp
@@ -101,4 +101,4 @@ statement
 
 
 atn:
-[4, 1, 37, 217, 2, 0, 7, 0, 2, 1, 7, 1, 2, 2, 7, 2, 2, 3, 7, 3, 2, 4, 7, 4, 2, 5, 7, 5, 2, 6, 7, 6, 2, 7, 7, 7, 2, 8, 7, 8, 2, 9, 7, 9, 2, 10, 7, 10, 2, 11, 7, 11, 2, 12, 7, 12, 2, 13, 7, 13, 2, 14, 7, 14, 2, 15, 7, 15, 2, 16, 7, 16, 2, 17, 7, 17, 2, 18, 7, 18, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 3, 1, 46, 8, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 3, 2, 56, 8, 2, 1, 2, 1, 2, 1, 2, 5, 2, 61, 8, 2, 10, 2, 12, 2, 64, 9, 2, 1, 3, 1, 3, 1, 3, 5, 3, 69, 8, 3, 10, 3, 12, 3, 72, 9, 3, 1, 4, 1, 4, 1, 4, 3, 4, 77, 8, 4, 1, 4, 1, 4, 1, 5, 1, 5, 1, 5, 1, 6, 1, 6, 1, 6, 3, 6, 87, 8, 6, 1, 7, 1, 7, 1, 7, 5, 7, 92, 8, 7, 10, 7, 12, 7, 95, 9, 7, 1, 7, 1, 7, 1, 8, 3, 8, 100, 8, 8, 1, 8, 5, 8, 103, 8, 8, 10, 8, 12, 8, 106, 9, 8, 1, 8, 1, 8, 1, 9, 1, 9, 1, 9, 1, 9, 1, 9, 1, 10, 1, 10, 1, 10, 3, 10, 118, 8, 10, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 4, 11, 135, 8, 11, 11, 11, 12, 11, 136, 1, 11, 1, 11, 1, 11, 1, 11, 5, 11, 143, 8, 11, 10, 11, 12, 11, 146, 9, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 3, 11, 154, 8, 11, 1, 12, 1, 12, 1, 12, 1, 12, 1, 13, 1, 13, 1, 13, 3, 13, 163, 8, 13, 1, 14, 1, 14, 1, 14, 1, 14, 1, 15, 1, 15, 1, 15, 4, 15, 172, 8, 15, 11, 15, 12, 15, 173, 1, 15, 1, 15, 1, 15, 1, 15, 5, 15, 180, 8, 15, 10, 15, 12, 15, 183, 9, 15, 1, 15, 1, 15, 1, 15, 1, 15, 3, 15, 189, 8, 15, 1, 16, 1, 16, 1, 16, 1, 17, 1, 17, 3, 17, 196, 8, 17, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 3, 18, 215, 8, 18, 1, 18, 0, 1, 4, 19, 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 0, 1, 2, 0, 1, 1, 29, 29, 228, 0, 38, 1, 0, 0, 0, 2, 45, 1, 0, 0, 0, 4, 55, 1, 0, 0, 0, 6, 65, 1, 0, 0, 0, 8, 73, 1, 0, 0, 0, 10, 80, 1, 0, 0, 0, 12, 83, 1, 0, 0, 0, 14, 88, 1, 0, 0, 0, 16, 99, 1, 0, 0, 0, 18, 109, 1, 0, 0, 0, 20, 117, 1, 0, 0, 0, 22, 153, 1, 0, 0, 0, 24, 155, 1, 0, 0, 0, 26, 162, 1, 0, 0, 0, 28, 164, 1, 0, 0, 0, 30, 188, 1, 0, 0, 0, 32, 190, 1, 0, 0, 0, 34, 195, 1, 0, 0, 0, 36, 214, 1, 0, 0, 0, 38, 39, 5, 22, 0, 0, 39, 40, 3, 4, 2, 0, 40, 41, 3, 4, 2, 0, 41, 42, 5, 23, 0, 0, 42, 1, 1, 0, 0, 0, 43, 46, 5, 30, 0, 0, 44, 46, 5, 31, 0, 0, 45, 43, 1, 0, 0, 0, 45, 44, 1, 0, 0, 0, 46, 3, 1, 0, 0, 0, 47, 48, 6, 2, -1, 0, 48, 56, 5, 35, 0, 0, 49, 56, 5, 37, 0, 0, 50, 56, 5, 32, 0, 0, 51, 56, 5, 36, 0, 0, 52, 56, 5, 34, 0, 0, 53, 56, 3, 0, 0, 0, 54, 56, 3, 2, 1, 0, 55, 47, 1, 0, 0, 0, 55, 49, 1, 0, 0, 0, 55, 50, 1, 0, 0, 0, 55, 51, 1, 0, 0, 0, 55, 52, 1, 0, 0, 0, 55, 53, 1, 0, 0, 0, 55, 54, 1, 0, 0, 0, 56, 62, 1, 0, 0, 0, 57, 58, 10, 1, 0, 0, 58, 59, 7, 0, 0, 0, 59, 61, 3, 4, 2, 2, 60, 57, 1, 0, 0, 0, 61, 64, 1, 0, 0, 0, 62, 60, 1, 0, 0, 0, 62, 63, 1, 0, 0, 0, 63, 5, 1, 0, 0, 0, 64, 62, 1, 0, 0, 0, 65, 70, 3, 4, 2, 0, 66, 67, 5, 26, 0, 0, 67, 69, 3, 4, 2, 0, 68, 66, 1, 0, 0, 0, 69, 72, 1, 0, 0, 0, 70, 68, 1, 0, 0, 0, 70, 71, 1, 0, 0, 0, 71, 7, 1, 0, 0, 0, 72, 70, 1, 0, 0, 0, 73, 74, 5, 33, 0, 0, 74, 76, 5, 20, 0, 0, 75, 77, 3, 6, 3, 0, 76, 75, 1, 0, 0, 0, 76, 77, 1, 0, 0, 0, 77, 78, 1, 0, 0, 0, 78, 79, 5, 21, 0, 0, 79, 9, 1, 0, 0, 0, 80, 81, 5, 27, 0, 0, 81, 82, 3, 8, 4, 0, 82, 11, 1, 0, 0, 0, 83, 84, 5, 33, 0, 0, 84, 86, 5, 35, 0, 0, 85, 87, 3, 10, 5, 0, 86, 85, 1, 0, 0, 0, 86, 87, 1, 0, 0, 0, 87, 13, 1, 0, 0, 0, 88, 89, 5, 6, 0, 0, 89, 93, 5, 24, 0, 0, 90, 92, 3, 12, 6, 0, 91, 90, 1, 0, 0, 0, 92, 95, 1, 0, 0, 0, 93, 91, 1, 0, 0, 0, 93, 94, 1, 0, 0, 0, 94, 96, 1, 0, 0, 0, 95, 93, 1, 0, 0, 0, 96, 97, 5, 25, 0, 0, 97, 15, 1, 0, 0, 0, 98, 100, 3, 14, 7, 0, 99, 98, 1, 0, 0, 0, 99, 100, 1, 0, 0, 0, 100, 104, 1, 0, 0, 0, 101, 103, 3, 36, 18, 0, 102, 101, 1, 0, 0, 0, 103, 106, 1, 0, 0, 0, 104, 102, 1, 0, 0, 0, 104, 105, 1, 0, 0, 0, 105, 107, 1, 0, 0, 0, 106, 104, 1, 0, 0, 0, 107, 108, 5, 0, 0, 1, 108, 17, 1, 0, 0, 0, 109, 110, 5, 22, 0, 0, 110, 111, 3, 4, 2, 0, 111, 112, 5, 28, 0, 0, 112, 113, 5, 23, 0, 0, 113, 19, 1, 0, 0, 0, 114, 118, 3, 2, 1, 0, 115, 118, 5, 35, 0, 0, 116, 118, 5, 14, 0, 0, 117, 114, 1, 0, 0, 0, 117, 115, 1, 0, 0, 0, 117, 116, 1, 0, 0, 0, 118, 21, 1, 0, 0, 0, 119, 120, 3, 4, 2, 0, 120, 121, 5, 15, 0, 0, 121, 122, 5, 16, 0, 0, 122, 123, 5, 17, 0, 0, 123, 154, 1, 0, 0, 0, 124, 125, 3, 4, 2, 0, 125, 126, 5, 15, 0, 0, 126, 127, 5, 17, 0, 0, 127, 128, 5, 12, 0, 0, 128, 129, 5, 13, 0, 0, 129, 130, 3, 4, 2, 0, 130, 154, 1, 0, 0, 0, 131, 154, 3, 4, 2, 0, 132, 134, 5, 24, 0, 0, 133, 135, 3, 24, 12, 0, 134, 133, 1, 0, 0, 0, 135, 136, 1, 0, 0, 0, 136, 134, 1, 0, 0, 0, 136, 137, 1, 0, 0, 0, 137, 138, 1, 0, 0, 0, 138, 139, 5, 25, 0, 0, 139, 154, 1, 0, 0, 0, 140, 144, 5, 24, 0, 0, 141, 143, 3, 22, 11, 0, 142, 141, 1, 0, 0, 0, 143, 146, 1, 0, 0, 0, 144, 142, 1, 0, 0, 0, 144, 145, 1, 0, 0, 0, 145, 147, 1, 0, 0, 0, 146, 144, 1, 0, 0, 0, 147, 154, 5, 25, 0, 0, 148, 149, 5, 7, 0, 0, 149, 150, 3, 4, 2, 0, 150, 151, 5, 11, 0, 0, 151, 152, 3, 22, 11, 0, 152, 154, 1, 0, 0, 0, 153, 119, 1, 0, 0, 0, 153, 124, 1, 0, 0, 0, 153, 131, 1, 0, 0, 0, 153, 132, 1, 0, 0, 0, 153, 140, 1, 0, 0, 0, 153, 148, 1, 0, 0, 0, 154, 23, 1, 0, 0, 0, 155, 156, 3, 20, 10, 0, 156, 157, 5, 11, 0, 0, 157, 158, 3, 22, 11, 0, 158, 25, 1, 0, 0, 0, 159, 160, 5, 13, 0, 0, 160, 163, 3, 30, 15, 0, 161, 163, 5, 18, 0, 0, 162, 159, 1, 0, 0, 0, 162, 161, 1, 0, 0, 0, 163, 27, 1, 0, 0, 0, 164, 165, 5, 7, 0, 0, 165, 166, 3, 4, 2, 0, 166, 167, 3, 26, 13, 0, 167, 29, 1, 0, 0, 0, 168, 189, 3, 4, 2, 0, 169, 171, 5, 24, 0, 0, 170, 172, 3, 32, 16, 0, 171, 170, 1, 0, 0, 0, 172, 173, 1, 0, 0, 0, 173, 171, 1, 0, 0, 0, 173, 174, 1, 0, 0, 0, 174, 175, 1, 0, 0, 0, 175, 176, 5, 25, 0, 0, 176, 189, 1, 0, 0, 0, 177, 181, 5, 24, 0, 0, 178, 180, 3, 28, 14, 0, 179, 178, 1, 0, 0, 0, 180, 183, 1, 0, 0, 0, 181, 179, 1, 0, 0, 0, 181, 182, 1, 0, 0, 0, 182, 184, 1, 0, 0, 0, 183, 181, 1, 0, 0, 0, 184, 185, 5, 14, 0, 0, 185, 186, 3, 26, 13, 0, 186, 187, 5, 25, 0, 0, 187, 189, 1, 0, 0, 0, 188, 168, 1, 0, 0, 0, 188, 169, 1, 0, 0, 0, 188, 177, 1, 0, 0, 0, 189, 31, 1, 0, 0, 0, 190, 191, 3, 20, 10, 0, 191, 192, 3, 26, 13, 0, 192, 33, 1, 0, 0, 0, 193, 196, 3, 4, 2, 0, 194, 196, 3, 18, 9, 0, 195, 193, 1, 0, 0, 0, 195, 194, 1, 0, 0, 0, 196, 35, 1, 0, 0, 0, 197, 198, 5, 10, 0, 0, 198, 199, 3, 34, 17, 0, 199, 200, 5, 20, 0, 0, 200, 201, 5, 8, 0, 0, 201, 202, 5, 27, 0, 0, 202, 203, 3, 22, 11, 0, 203, 204, 5, 9, 0, 0, 204, 205, 5, 27, 0, 0, 205, 206, 3, 30, 15, 0, 206, 207, 5, 21, 0, 0, 207, 215, 1, 0, 0, 0, 208, 209, 5, 19, 0, 0, 209, 210, 3, 34, 17, 0, 210, 211, 5, 11, 0, 0, 211, 212, 3, 4, 2, 0, 212, 215, 1, 0, 0, 0, 213, 215, 3, 8, 4, 0, 214, 197, 1, 0, 0, 0, 214, 208, 1, 0, 0, 0, 214, 213, 1, 0, 0, 0, 215, 37, 1, 0, 0, 0, 19, 45, 55, 62, 70, 76, 86, 93, 99, 104, 117, 136, 144, 153, 162, 173, 181, 188, 195, 214]
\ No newline at end of file
+[4, 1, 37, 217, 2, 0, 7, 0, 2, 1, 7, 1, 2, 2, 7, 2, 2, 3, 7, 3, 2, 4, 7, 4, 2, 5, 7, 5, 2, 6, 7, 6, 2, 7, 7, 7, 2, 8, 7, 8, 2, 9, 7, 9, 2, 10, 7, 10, 2, 11, 7, 11, 2, 12, 7, 12, 2, 13, 7, 13, 2, 14, 7, 14, 2, 15, 7, 15, 2, 16, 7, 16, 2, 17, 7, 17, 2, 18, 7, 18, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 3, 1, 46, 8, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 3, 2, 56, 8, 2, 1, 2, 1, 2, 1, 2, 5, 2, 61, 8, 2, 10, 2, 12, 2, 64, 9, 2, 1, 3, 1, 3, 1, 3, 5, 3, 69, 8, 3, 10, 3, 12, 3, 72, 9, 3, 1, 4, 1, 4, 1, 4, 3, 4, 77, 8, 4, 1, 4, 1, 4, 1, 5, 1, 5, 1, 5, 1, 6, 1, 6, 1, 6, 3, 6, 87, 8, 6, 1, 7, 1, 7, 1, 7, 5, 7, 92, 8, 7, 10, 7, 12, 7, 95, 9, 7, 1, 7, 1, 7, 1, 8, 3, 8, 100, 8, 8, 1, 8, 5, 8, 103, 8, 8, 10, 8, 12, 8, 106, 9, 8, 1, 8, 1, 8, 1, 9, 1, 9, 1, 9, 1, 9, 1, 9, 1, 10, 1, 10, 1, 10, 3, 10, 118, 8, 10, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 4, 11, 135, 8, 11, 11, 11, 12, 11, 136, 1, 11, 1, 11, 1, 11, 1, 11, 5, 11, 143, 8, 11, 10, 11, 12, 11, 146, 9, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 1, 11, 3, 11, 154, 8, 11, 1, 12, 1, 12, 1, 12, 1, 12, 1, 13, 1, 13, 1, 13, 3, 13, 163, 8, 13, 1, 14, 1, 14, 1, 14, 1, 14, 1, 15, 1, 15, 1, 15, 4, 15, 172, 8, 15, 11, 15, 12, 15, 173, 1, 15, 1, 15, 1, 15, 1, 15, 5, 15, 180, 8, 15, 10, 15, 12, 15, 183, 9, 15, 1, 15, 1, 15, 1, 15, 1, 15, 3, 15, 189, 8, 15, 1, 16, 1, 16, 1, 16, 1, 17, 1, 17, 3, 17, 196, 8, 17, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 3, 18, 215, 8, 18, 1, 18, 0, 1, 4, 19, 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 0, 2, 2, 0, 1, 1, 29, 29, 2, 0, 17, 17, 33, 33, 228, 0, 38, 1, 0, 0, 0, 2, 45, 1, 0, 0, 0, 4, 55, 1, 0, 0, 0, 6, 65, 1, 0, 0, 0, 8, 73, 1, 0, 0, 0, 10, 80, 1, 0, 0, 0, 12, 83, 1, 0, 0, 0, 14, 88, 1, 0, 0, 0, 16, 99, 1, 0, 0, 0, 18, 109, 1, 0, 0, 0, 20, 117, 1, 0, 0, 0, 22, 153, 1, 0, 0, 0, 24, 155, 1, 0, 0, 0, 26, 162, 1, 0, 0, 0, 28, 164, 1, 0, 0, 0, 30, 188, 1, 0, 0, 0, 32, 190, 1, 0, 0, 0, 34, 195, 1, 0, 0, 0, 36, 214, 1, 0, 0, 0, 38, 39, 5, 22, 0, 0, 39, 40, 3, 4, 2, 0, 40, 41, 3, 4, 2, 0, 41, 42, 5, 23, 0, 0, 42, 1, 1, 0, 0, 0, 43, 46, 5, 30, 0, 0, 44, 46, 5, 31, 0, 0, 45, 43, 1, 0, 0, 0, 45, 44, 1, 0, 0, 0, 46, 3, 1, 0, 0, 0, 47, 48, 6, 2, -1, 0, 48, 56, 5, 35, 0, 0, 49, 56, 5, 37, 0, 0, 50, 56, 5, 32, 0, 0, 51, 56, 5, 36, 0, 0, 52, 56, 5, 34, 0, 0, 53, 56, 3, 0, 0, 0, 54, 56, 3, 2, 1, 0, 55, 47, 1, 0, 0, 0, 55, 49, 1, 0, 0, 0, 55, 50, 1, 0, 0, 0, 55, 51, 1, 0, 0, 0, 55, 52, 1, 0, 0, 0, 55, 53, 1, 0, 0, 0, 55, 54, 1, 0, 0, 0, 56, 62, 1, 0, 0, 0, 57, 58, 10, 1, 0, 0, 58, 59, 7, 0, 0, 0, 59, 61, 3, 4, 2, 2, 60, 57, 1, 0, 0, 0, 61, 64, 1, 0, 0, 0, 62, 60, 1, 0, 0, 0, 62, 63, 1, 0, 0, 0, 63, 5, 1, 0, 0, 0, 64, 62, 1, 0, 0, 0, 65, 70, 3, 4, 2, 0, 66, 67, 5, 26, 0, 0, 67, 69, 3, 4, 2, 0, 68, 66, 1, 0, 0, 0, 69, 72, 1, 0, 0, 0, 70, 68, 1, 0, 0, 0, 70, 71, 1, 0, 0, 0, 71, 7, 1, 0, 0, 0, 72, 70, 1, 0, 0, 0, 73, 74, 7, 1, 0, 0, 74, 76, 5, 20, 0, 0, 75, 77, 3, 6, 3, 0, 76, 75, 1, 0, 0, 0, 76, 77, 1, 0, 0, 0, 77, 78, 1, 0, 0, 0, 78, 79, 5, 21, 0, 0, 79, 9, 1, 0, 0, 0, 80, 81, 5, 27, 0, 0, 81, 82, 3, 8, 4, 0, 82, 11, 1, 0, 0, 0, 83, 84, 5, 33, 0, 0, 84, 86, 5, 35, 0, 0, 85, 87, 3, 10, 5, 0, 86, 85, 1, 0, 0, 0, 86, 87, 1, 0, 0, 0, 87, 13, 1, 0, 0, 0, 88, 89, 5, 6, 0, 0, 89, 93, 5, 24, 0, 0, 90, 92, 3, 12, 6, 0, 91, 90, 1, 0, 0, 0, 92, 95, 1, 0, 0, 0, 93, 91, 1, 0, 0, 0, 93, 94, 1, 0, 0, 0, 94, 96, 1, 0, 0, 0, 95, 93, 1, 0, 0, 0, 96, 97, 5, 25, 0, 0, 97, 15, 1, 0, 0, 0, 98, 100, 3, 14, 7, 0, 99, 98, 1, 0, 0, 0, 99, 100, 1, 0, 0, 0, 100, 104, 1, 0, 0, 0, 101, 103, 3, 36, 18, 0, 102, 101, 1, 0, 0, 0, 103, 106, 1, 0, 0, 0, 104, 102, 1, 0, 0, 0, 104, 105, 1, 0, 0, 0, 105, 107, 1, 0, 0, 0, 106, 104, 1, 0, 0, 0, 107, 108, 5, 0, 0, 1, 108, 17, 1, 0, 0, 0, 109, 110, 5, 22, 0, 0, 110, 111, 3, 4, 2, 0, 111, 112, 5, 28, 0, 0, 112, 113, 5, 23, 0, 0, 113, 19, 1, 0, 0, 0, 114, 118, 3, 2, 1, 0, 115, 118, 5, 35, 0, 0, 116, 118, 5, 14, 0, 0, 117, 114, 1, 0, 0, 0, 117, 115, 1, 0, 0, 0, 117, 116, 1, 0, 0, 0, 118, 21, 1, 0, 0, 0, 119, 120, 3, 4, 2, 0, 120, 121, 5, 15, 0, 0, 121, 122, 5, 16, 0, 0, 122, 123, 5, 17, 0, 0, 123, 154, 1, 0, 0, 0, 124, 125, 3, 4, 2, 0, 125, 126, 5, 15, 0, 0, 126, 127, 5, 17, 0, 0, 127, 128, 5, 12, 0, 0, 128, 129, 5, 13, 0, 0, 129, 130, 3, 4, 2, 0, 130, 154, 1, 0, 0, 0, 131, 154, 3, 4, 2, 0, 132, 134, 5, 24, 0, 0, 133, 135, 3, 24, 12, 0, 134, 133, 1, 0, 0, 0, 135, 136, 1, 0, 0, 0, 136, 134, 1, 0, 0, 0, 136, 137, 1, 0, 0, 0, 137, 138, 1, 0, 0, 0, 138, 139, 5, 25, 0, 0, 139, 154, 1, 0, 0, 0, 140, 144, 5, 24, 0, 0, 141, 143, 3, 22, 11, 0, 142, 141, 1, 0, 0, 0, 143, 146, 1, 0, 0, 0, 144, 142, 1, 0, 0, 0, 144, 145, 1, 0, 0, 0, 145, 147, 1, 0, 0, 0, 146, 144, 1, 0, 0, 0, 147, 154, 5, 25, 0, 0, 148, 149, 5, 7, 0, 0, 149, 150, 3, 4, 2, 0, 150, 151, 5, 11, 0, 0, 151, 152, 3, 22, 11, 0, 152, 154, 1, 0, 0, 0, 153, 119, 1, 0, 0, 0, 153, 124, 1, 0, 0, 0, 153, 131, 1, 0, 0, 0, 153, 132, 1, 0, 0, 0, 153, 140, 1, 0, 0, 0, 153, 148, 1, 0, 0, 0, 154, 23, 1, 0, 0, 0, 155, 156, 3, 20, 10, 0, 156, 157, 5, 11, 0, 0, 157, 158, 3, 22, 11, 0, 158, 25, 1, 0, 0, 0, 159, 160, 5, 13, 0, 0, 160, 163, 3, 30, 15, 0, 161, 163, 5, 18, 0, 0, 162, 159, 1, 0, 0, 0, 162, 161, 1, 0, 0, 0, 163, 27, 1, 0, 0, 0, 164, 165, 5, 7, 0, 0, 165, 166, 3, 4, 2, 0, 166, 167, 3, 26, 13, 0, 167, 29, 1, 0, 0, 0, 168, 189, 3, 4, 2, 0, 169, 171, 5, 24, 0, 0, 170, 172, 3, 32, 16, 0, 171, 170, 1, 0, 0, 0, 172, 173, 1, 0, 0, 0, 173, 171, 1, 0, 0, 0, 173, 174, 1, 0, 0, 0, 174, 175, 1, 0, 0, 0, 175, 176, 5, 25, 0, 0, 176, 189, 1, 0, 0, 0, 177, 181, 5, 24, 0, 0, 178, 180, 3, 28, 14, 0, 179, 178, 1, 0, 0, 0, 180, 183, 1, 0, 0, 0, 181, 179, 1, 0, 0, 0, 181, 182, 1, 0, 0, 0, 182, 184, 1, 0, 0, 0, 183, 181, 1, 0, 0, 0, 184, 185, 5, 14, 0, 0, 185, 186, 3, 26, 13, 0, 186, 187, 5, 25, 0, 0, 187, 189, 1, 0, 0, 0, 188, 168, 1, 0, 0, 0, 188, 169, 1, 0, 0, 0, 188, 177, 1, 0, 0, 0, 189, 31, 1, 0, 0, 0, 190, 191, 3, 20, 10, 0, 191, 192, 3, 26, 13, 0, 192, 33, 1, 0, 0, 0, 193, 196, 3, 4, 2, 0, 194, 196, 3, 18, 9, 0, 195, 193, 1, 0, 0, 0, 195, 194, 1, 0, 0, 0, 196, 35, 1, 0, 0, 0, 197, 198, 5, 10, 0, 0, 198, 199, 3, 34, 17, 0, 199, 200, 5, 20, 0, 0, 200, 201, 5, 8, 0, 0, 201, 202, 5, 27, 0, 0, 202, 203, 3, 22, 11, 0, 203, 204, 5, 9, 0, 0, 204, 205, 5, 27, 0, 0, 205, 206, 3, 30, 15, 0, 206, 207, 5, 21, 0, 0, 207, 215, 1, 0, 0, 0, 208, 209, 5, 19, 0, 0, 209, 210, 3, 34, 17, 0, 210, 211, 5, 11, 0, 0, 211, 212, 3, 4, 2, 0, 212, 215, 1, 0, 0, 0, 213, 215, 3, 8, 4, 0, 214, 197, 1, 0, 0, 0, 214, 208, 1, 0, 0, 0, 214, 213, 1, 0, 0, 0, 215, 37, 1, 0, 0, 0, 19, 45, 55, 62, 70, 76, 86, 93, 99, 104, 117, 136, 144, 153, 162, 173, 181, 188, 195, 214]
\ No newline at end of file
diff --git a/internal/parser/antlr/numscript_parser.go b/internal/parser/antlr/numscript_parser.go
index 4fefc7b..542cd8b 100644
--- a/internal/parser/antlr/numscript_parser.go
+++ b/internal/parser/antlr/numscript_parser.go
@@ -77,76 +77,76 @@ func numscriptParserInit() {
 		18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 1, 18,
 		1, 18, 1, 18, 1, 18, 1, 18, 1, 18, 3, 18, 215, 8, 18, 1, 18, 0, 1, 4, 19,
 		0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36,
-		0, 1, 2, 0, 1, 1, 29, 29, 228, 0, 38, 1, 0, 0, 0, 2, 45, 1, 0, 0, 0, 4,
-		55, 1, 0, 0, 0, 6, 65, 1, 0, 0, 0, 8, 73, 1, 0, 0, 0, 10, 80, 1, 0, 0,
-		0, 12, 83, 1, 0, 0, 0, 14, 88, 1, 0, 0, 0, 16, 99, 1, 0, 0, 0, 18, 109,
-		1, 0, 0, 0, 20, 117, 1, 0, 0, 0, 22, 153, 1, 0, 0, 0, 24, 155, 1, 0, 0,
-		0, 26, 162, 1, 0, 0, 0, 28, 164, 1, 0, 0, 0, 30, 188, 1, 0, 0, 0, 32, 190,
-		1, 0, 0, 0, 34, 195, 1, 0, 0, 0, 36, 214, 1, 0, 0, 0, 38, 39, 5, 22, 0,
-		0, 39, 40, 3, 4, 2, 0, 40, 41, 3, 4, 2, 0, 41, 42, 5, 23, 0, 0, 42, 1,
-		1, 0, 0, 0, 43, 46, 5, 30, 0, 0, 44, 46, 5, 31, 0, 0, 45, 43, 1, 0, 0,
-		0, 45, 44, 1, 0, 0, 0, 46, 3, 1, 0, 0, 0, 47, 48, 6, 2, -1, 0, 48, 56,
-		5, 35, 0, 0, 49, 56, 5, 37, 0, 0, 50, 56, 5, 32, 0, 0, 51, 56, 5, 36, 0,
-		0, 52, 56, 5, 34, 0, 0, 53, 56, 3, 0, 0, 0, 54, 56, 3, 2, 1, 0, 55, 47,
-		1, 0, 0, 0, 55, 49, 1, 0, 0, 0, 55, 50, 1, 0, 0, 0, 55, 51, 1, 0, 0, 0,
-		55, 52, 1, 0, 0, 0, 55, 53, 1, 0, 0, 0, 55, 54, 1, 0, 0, 0, 56, 62, 1,
-		0, 0, 0, 57, 58, 10, 1, 0, 0, 58, 59, 7, 0, 0, 0, 59, 61, 3, 4, 2, 2, 60,
-		57, 1, 0, 0, 0, 61, 64, 1, 0, 0, 0, 62, 60, 1, 0, 0, 0, 62, 63, 1, 0, 0,
-		0, 63, 5, 1, 0, 0, 0, 64, 62, 1, 0, 0, 0, 65, 70, 3, 4, 2, 0, 66, 67, 5,
-		26, 0, 0, 67, 69, 3, 4, 2, 0, 68, 66, 1, 0, 0, 0, 69, 72, 1, 0, 0, 0, 70,
-		68, 1, 0, 0, 0, 70, 71, 1, 0, 0, 0, 71, 7, 1, 0, 0, 0, 72, 70, 1, 0, 0,
-		0, 73, 74, 5, 33, 0, 0, 74, 76, 5, 20, 0, 0, 75, 77, 3, 6, 3, 0, 76, 75,
-		1, 0, 0, 0, 76, 77, 1, 0, 0, 0, 77, 78, 1, 0, 0, 0, 78, 79, 5, 21, 0, 0,
-		79, 9, 1, 0, 0, 0, 80, 81, 5, 27, 0, 0, 81, 82, 3, 8, 4, 0, 82, 11, 1,
-		0, 0, 0, 83, 84, 5, 33, 0, 0, 84, 86, 5, 35, 0, 0, 85, 87, 3, 10, 5, 0,
-		86, 85, 1, 0, 0, 0, 86, 87, 1, 0, 0, 0, 87, 13, 1, 0, 0, 0, 88, 89, 5,
-		6, 0, 0, 89, 93, 5, 24, 0, 0, 90, 92, 3, 12, 6, 0, 91, 90, 1, 0, 0, 0,
-		92, 95, 1, 0, 0, 0, 93, 91, 1, 0, 0, 0, 93, 94, 1, 0, 0, 0, 94, 96, 1,
-		0, 0, 0, 95, 93, 1, 0, 0, 0, 96, 97, 5, 25, 0, 0, 97, 15, 1, 0, 0, 0, 98,
-		100, 3, 14, 7, 0, 99, 98, 1, 0, 0, 0, 99, 100, 1, 0, 0, 0, 100, 104, 1,
-		0, 0, 0, 101, 103, 3, 36, 18, 0, 102, 101, 1, 0, 0, 0, 103, 106, 1, 0,
-		0, 0, 104, 102, 1, 0, 0, 0, 104, 105, 1, 0, 0, 0, 105, 107, 1, 0, 0, 0,
-		106, 104, 1, 0, 0, 0, 107, 108, 5, 0, 0, 1, 108, 17, 1, 0, 0, 0, 109, 110,
-		5, 22, 0, 0, 110, 111, 3, 4, 2, 0, 111, 112, 5, 28, 0, 0, 112, 113, 5,
-		23, 0, 0, 113, 19, 1, 0, 0, 0, 114, 118, 3, 2, 1, 0, 115, 118, 5, 35, 0,
-		0, 116, 118, 5, 14, 0, 0, 117, 114, 1, 0, 0, 0, 117, 115, 1, 0, 0, 0, 117,
-		116, 1, 0, 0, 0, 118, 21, 1, 0, 0, 0, 119, 120, 3, 4, 2, 0, 120, 121, 5,
-		15, 0, 0, 121, 122, 5, 16, 0, 0, 122, 123, 5, 17, 0, 0, 123, 154, 1, 0,
-		0, 0, 124, 125, 3, 4, 2, 0, 125, 126, 5, 15, 0, 0, 126, 127, 5, 17, 0,
-		0, 127, 128, 5, 12, 0, 0, 128, 129, 5, 13, 0, 0, 129, 130, 3, 4, 2, 0,
-		130, 154, 1, 0, 0, 0, 131, 154, 3, 4, 2, 0, 132, 134, 5, 24, 0, 0, 133,
-		135, 3, 24, 12, 0, 134, 133, 1, 0, 0, 0, 135, 136, 1, 0, 0, 0, 136, 134,
-		1, 0, 0, 0, 136, 137, 1, 0, 0, 0, 137, 138, 1, 0, 0, 0, 138, 139, 5, 25,
-		0, 0, 139, 154, 1, 0, 0, 0, 140, 144, 5, 24, 0, 0, 141, 143, 3, 22, 11,
-		0, 142, 141, 1, 0, 0, 0, 143, 146, 1, 0, 0, 0, 144, 142, 1, 0, 0, 0, 144,
-		145, 1, 0, 0, 0, 145, 147, 1, 0, 0, 0, 146, 144, 1, 0, 0, 0, 147, 154,
-		5, 25, 0, 0, 148, 149, 5, 7, 0, 0, 149, 150, 3, 4, 2, 0, 150, 151, 5, 11,
-		0, 0, 151, 152, 3, 22, 11, 0, 152, 154, 1, 0, 0, 0, 153, 119, 1, 0, 0,
-		0, 153, 124, 1, 0, 0, 0, 153, 131, 1, 0, 0, 0, 153, 132, 1, 0, 0, 0, 153,
-		140, 1, 0, 0, 0, 153, 148, 1, 0, 0, 0, 154, 23, 1, 0, 0, 0, 155, 156, 3,
-		20, 10, 0, 156, 157, 5, 11, 0, 0, 157, 158, 3, 22, 11, 0, 158, 25, 1, 0,
-		0, 0, 159, 160, 5, 13, 0, 0, 160, 163, 3, 30, 15, 0, 161, 163, 5, 18, 0,
-		0, 162, 159, 1, 0, 0, 0, 162, 161, 1, 0, 0, 0, 163, 27, 1, 0, 0, 0, 164,
-		165, 5, 7, 0, 0, 165, 166, 3, 4, 2, 0, 166, 167, 3, 26, 13, 0, 167, 29,
-		1, 0, 0, 0, 168, 189, 3, 4, 2, 0, 169, 171, 5, 24, 0, 0, 170, 172, 3, 32,
-		16, 0, 171, 170, 1, 0, 0, 0, 172, 173, 1, 0, 0, 0, 173, 171, 1, 0, 0, 0,
-		173, 174, 1, 0, 0, 0, 174, 175, 1, 0, 0, 0, 175, 176, 5, 25, 0, 0, 176,
-		189, 1, 0, 0, 0, 177, 181, 5, 24, 0, 0, 178, 180, 3, 28, 14, 0, 179, 178,
-		1, 0, 0, 0, 180, 183, 1, 0, 0, 0, 181, 179, 1, 0, 0, 0, 181, 182, 1, 0,
-		0, 0, 182, 184, 1, 0, 0, 0, 183, 181, 1, 0, 0, 0, 184, 185, 5, 14, 0, 0,
-		185, 186, 3, 26, 13, 0, 186, 187, 5, 25, 0, 0, 187, 189, 1, 0, 0, 0, 188,
-		168, 1, 0, 0, 0, 188, 169, 1, 0, 0, 0, 188, 177, 1, 0, 0, 0, 189, 31, 1,
-		0, 0, 0, 190, 191, 3, 20, 10, 0, 191, 192, 3, 26, 13, 0, 192, 33, 1, 0,
-		0, 0, 193, 196, 3, 4, 2, 0, 194, 196, 3, 18, 9, 0, 195, 193, 1, 0, 0, 0,
-		195, 194, 1, 0, 0, 0, 196, 35, 1, 0, 0, 0, 197, 198, 5, 10, 0, 0, 198,
-		199, 3, 34, 17, 0, 199, 200, 5, 20, 0, 0, 200, 201, 5, 8, 0, 0, 201, 202,
-		5, 27, 0, 0, 202, 203, 3, 22, 11, 0, 203, 204, 5, 9, 0, 0, 204, 205, 5,
-		27, 0, 0, 205, 206, 3, 30, 15, 0, 206, 207, 5, 21, 0, 0, 207, 215, 1, 0,
-		0, 0, 208, 209, 5, 19, 0, 0, 209, 210, 3, 34, 17, 0, 210, 211, 5, 11, 0,
-		0, 211, 212, 3, 4, 2, 0, 212, 215, 1, 0, 0, 0, 213, 215, 3, 8, 4, 0, 214,
-		197, 1, 0, 0, 0, 214, 208, 1, 0, 0, 0, 214, 213, 1, 0, 0, 0, 215, 37, 1,
-		0, 0, 0, 19, 45, 55, 62, 70, 76, 86, 93, 99, 104, 117, 136, 144, 153, 162,
-		173, 181, 188, 195, 214,
+		0, 2, 2, 0, 1, 1, 29, 29, 2, 0, 17, 17, 33, 33, 228, 0, 38, 1, 0, 0, 0,
+		2, 45, 1, 0, 0, 0, 4, 55, 1, 0, 0, 0, 6, 65, 1, 0, 0, 0, 8, 73, 1, 0, 0,
+		0, 10, 80, 1, 0, 0, 0, 12, 83, 1, 0, 0, 0, 14, 88, 1, 0, 0, 0, 16, 99,
+		1, 0, 0, 0, 18, 109, 1, 0, 0, 0, 20, 117, 1, 0, 0, 0, 22, 153, 1, 0, 0,
+		0, 24, 155, 1, 0, 0, 0, 26, 162, 1, 0, 0, 0, 28, 164, 1, 0, 0, 0, 30, 188,
+		1, 0, 0, 0, 32, 190, 1, 0, 0, 0, 34, 195, 1, 0, 0, 0, 36, 214, 1, 0, 0,
+		0, 38, 39, 5, 22, 0, 0, 39, 40, 3, 4, 2, 0, 40, 41, 3, 4, 2, 0, 41, 42,
+		5, 23, 0, 0, 42, 1, 1, 0, 0, 0, 43, 46, 5, 30, 0, 0, 44, 46, 5, 31, 0,
+		0, 45, 43, 1, 0, 0, 0, 45, 44, 1, 0, 0, 0, 46, 3, 1, 0, 0, 0, 47, 48, 6,
+		2, -1, 0, 48, 56, 5, 35, 0, 0, 49, 56, 5, 37, 0, 0, 50, 56, 5, 32, 0, 0,
+		51, 56, 5, 36, 0, 0, 52, 56, 5, 34, 0, 0, 53, 56, 3, 0, 0, 0, 54, 56, 3,
+		2, 1, 0, 55, 47, 1, 0, 0, 0, 55, 49, 1, 0, 0, 0, 55, 50, 1, 0, 0, 0, 55,
+		51, 1, 0, 0, 0, 55, 52, 1, 0, 0, 0, 55, 53, 1, 0, 0, 0, 55, 54, 1, 0, 0,
+		0, 56, 62, 1, 0, 0, 0, 57, 58, 10, 1, 0, 0, 58, 59, 7, 0, 0, 0, 59, 61,
+		3, 4, 2, 2, 60, 57, 1, 0, 0, 0, 61, 64, 1, 0, 0, 0, 62, 60, 1, 0, 0, 0,
+		62, 63, 1, 0, 0, 0, 63, 5, 1, 0, 0, 0, 64, 62, 1, 0, 0, 0, 65, 70, 3, 4,
+		2, 0, 66, 67, 5, 26, 0, 0, 67, 69, 3, 4, 2, 0, 68, 66, 1, 0, 0, 0, 69,
+		72, 1, 0, 0, 0, 70, 68, 1, 0, 0, 0, 70, 71, 1, 0, 0, 0, 71, 7, 1, 0, 0,
+		0, 72, 70, 1, 0, 0, 0, 73, 74, 7, 1, 0, 0, 74, 76, 5, 20, 0, 0, 75, 77,
+		3, 6, 3, 0, 76, 75, 1, 0, 0, 0, 76, 77, 1, 0, 0, 0, 77, 78, 1, 0, 0, 0,
+		78, 79, 5, 21, 0, 0, 79, 9, 1, 0, 0, 0, 80, 81, 5, 27, 0, 0, 81, 82, 3,
+		8, 4, 0, 82, 11, 1, 0, 0, 0, 83, 84, 5, 33, 0, 0, 84, 86, 5, 35, 0, 0,
+		85, 87, 3, 10, 5, 0, 86, 85, 1, 0, 0, 0, 86, 87, 1, 0, 0, 0, 87, 13, 1,
+		0, 0, 0, 88, 89, 5, 6, 0, 0, 89, 93, 5, 24, 0, 0, 90, 92, 3, 12, 6, 0,
+		91, 90, 1, 0, 0, 0, 92, 95, 1, 0, 0, 0, 93, 91, 1, 0, 0, 0, 93, 94, 1,
+		0, 0, 0, 94, 96, 1, 0, 0, 0, 95, 93, 1, 0, 0, 0, 96, 97, 5, 25, 0, 0, 97,
+		15, 1, 0, 0, 0, 98, 100, 3, 14, 7, 0, 99, 98, 1, 0, 0, 0, 99, 100, 1, 0,
+		0, 0, 100, 104, 1, 0, 0, 0, 101, 103, 3, 36, 18, 0, 102, 101, 1, 0, 0,
+		0, 103, 106, 1, 0, 0, 0, 104, 102, 1, 0, 0, 0, 104, 105, 1, 0, 0, 0, 105,
+		107, 1, 0, 0, 0, 106, 104, 1, 0, 0, 0, 107, 108, 5, 0, 0, 1, 108, 17, 1,
+		0, 0, 0, 109, 110, 5, 22, 0, 0, 110, 111, 3, 4, 2, 0, 111, 112, 5, 28,
+		0, 0, 112, 113, 5, 23, 0, 0, 113, 19, 1, 0, 0, 0, 114, 118, 3, 2, 1, 0,
+		115, 118, 5, 35, 0, 0, 116, 118, 5, 14, 0, 0, 117, 114, 1, 0, 0, 0, 117,
+		115, 1, 0, 0, 0, 117, 116, 1, 0, 0, 0, 118, 21, 1, 0, 0, 0, 119, 120, 3,
+		4, 2, 0, 120, 121, 5, 15, 0, 0, 121, 122, 5, 16, 0, 0, 122, 123, 5, 17,
+		0, 0, 123, 154, 1, 0, 0, 0, 124, 125, 3, 4, 2, 0, 125, 126, 5, 15, 0, 0,
+		126, 127, 5, 17, 0, 0, 127, 128, 5, 12, 0, 0, 128, 129, 5, 13, 0, 0, 129,
+		130, 3, 4, 2, 0, 130, 154, 1, 0, 0, 0, 131, 154, 3, 4, 2, 0, 132, 134,
+		5, 24, 0, 0, 133, 135, 3, 24, 12, 0, 134, 133, 1, 0, 0, 0, 135, 136, 1,
+		0, 0, 0, 136, 134, 1, 0, 0, 0, 136, 137, 1, 0, 0, 0, 137, 138, 1, 0, 0,
+		0, 138, 139, 5, 25, 0, 0, 139, 154, 1, 0, 0, 0, 140, 144, 5, 24, 0, 0,
+		141, 143, 3, 22, 11, 0, 142, 141, 1, 0, 0, 0, 143, 146, 1, 0, 0, 0, 144,
+		142, 1, 0, 0, 0, 144, 145, 1, 0, 0, 0, 145, 147, 1, 0, 0, 0, 146, 144,
+		1, 0, 0, 0, 147, 154, 5, 25, 0, 0, 148, 149, 5, 7, 0, 0, 149, 150, 3, 4,
+		2, 0, 150, 151, 5, 11, 0, 0, 151, 152, 3, 22, 11, 0, 152, 154, 1, 0, 0,
+		0, 153, 119, 1, 0, 0, 0, 153, 124, 1, 0, 0, 0, 153, 131, 1, 0, 0, 0, 153,
+		132, 1, 0, 0, 0, 153, 140, 1, 0, 0, 0, 153, 148, 1, 0, 0, 0, 154, 23, 1,
+		0, 0, 0, 155, 156, 3, 20, 10, 0, 156, 157, 5, 11, 0, 0, 157, 158, 3, 22,
+		11, 0, 158, 25, 1, 0, 0, 0, 159, 160, 5, 13, 0, 0, 160, 163, 3, 30, 15,
+		0, 161, 163, 5, 18, 0, 0, 162, 159, 1, 0, 0, 0, 162, 161, 1, 0, 0, 0, 163,
+		27, 1, 0, 0, 0, 164, 165, 5, 7, 0, 0, 165, 166, 3, 4, 2, 0, 166, 167, 3,
+		26, 13, 0, 167, 29, 1, 0, 0, 0, 168, 189, 3, 4, 2, 0, 169, 171, 5, 24,
+		0, 0, 170, 172, 3, 32, 16, 0, 171, 170, 1, 0, 0, 0, 172, 173, 1, 0, 0,
+		0, 173, 171, 1, 0, 0, 0, 173, 174, 1, 0, 0, 0, 174, 175, 1, 0, 0, 0, 175,
+		176, 5, 25, 0, 0, 176, 189, 1, 0, 0, 0, 177, 181, 5, 24, 0, 0, 178, 180,
+		3, 28, 14, 0, 179, 178, 1, 0, 0, 0, 180, 183, 1, 0, 0, 0, 181, 179, 1,
+		0, 0, 0, 181, 182, 1, 0, 0, 0, 182, 184, 1, 0, 0, 0, 183, 181, 1, 0, 0,
+		0, 184, 185, 5, 14, 0, 0, 185, 186, 3, 26, 13, 0, 186, 187, 5, 25, 0, 0,
+		187, 189, 1, 0, 0, 0, 188, 168, 1, 0, 0, 0, 188, 169, 1, 0, 0, 0, 188,
+		177, 1, 0, 0, 0, 189, 31, 1, 0, 0, 0, 190, 191, 3, 20, 10, 0, 191, 192,
+		3, 26, 13, 0, 192, 33, 1, 0, 0, 0, 193, 196, 3, 4, 2, 0, 194, 196, 3, 18,
+		9, 0, 195, 193, 1, 0, 0, 0, 195, 194, 1, 0, 0, 0, 196, 35, 1, 0, 0, 0,
+		197, 198, 5, 10, 0, 0, 198, 199, 3, 34, 17, 0, 199, 200, 5, 20, 0, 0, 200,
+		201, 5, 8, 0, 0, 201, 202, 5, 27, 0, 0, 202, 203, 3, 22, 11, 0, 203, 204,
+		5, 9, 0, 0, 204, 205, 5, 27, 0, 0, 205, 206, 3, 30, 15, 0, 206, 207, 5,
+		21, 0, 0, 207, 215, 1, 0, 0, 0, 208, 209, 5, 19, 0, 0, 209, 210, 3, 34,
+		17, 0, 210, 211, 5, 11, 0, 0, 211, 212, 3, 4, 2, 0, 212, 215, 1, 0, 0,
+		0, 213, 215, 3, 8, 4, 0, 214, 197, 1, 0, 0, 0, 214, 208, 1, 0, 0, 0, 214,
+		213, 1, 0, 0, 0, 215, 37, 1, 0, 0, 0, 19, 45, 55, 62, 70, 76, 86, 93, 99,
+		104, 117, 136, 144, 153, 162, 173, 181, 188, 195, 214,
 	}
 	deserializer := antlr.NewATNDeserializer(nil)
 	staticData.atn = deserializer.Deserialize(staticData.serializedATN)
@@ -1385,10 +1385,17 @@ type IFunctionCallContext interface {
 	// GetParser returns the parser.
 	GetParser() antlr.Parser
 
+	// GetFnName returns the fnName token.
+	GetFnName() antlr.Token
+
+	// SetFnName sets the fnName token.
+	SetFnName(antlr.Token)
+
 	// Getter signatures
-	IDENTIFIER() antlr.TerminalNode
 	LPARENS() antlr.TerminalNode
 	RPARENS() antlr.TerminalNode
+	OVERDRAFT() antlr.TerminalNode
+	IDENTIFIER() antlr.TerminalNode
 	FunctionCallArgs() IFunctionCallArgsContext
 
 	// IsFunctionCallContext differentiates from other interfaces.
@@ -1398,6 +1405,7 @@ type IFunctionCallContext interface {
 type FunctionCallContext struct {
 	antlr.BaseParserRuleContext
 	parser antlr.Parser
+	fnName antlr.Token
 }
 
 func NewEmptyFunctionCallContext() *FunctionCallContext {
@@ -1427,9 +1435,9 @@ func NewFunctionCallContext(parser antlr.Parser, parent antlr.ParserRuleContext,
 
 func (s *FunctionCallContext) GetParser() antlr.Parser { return s.parser }
 
-func (s *FunctionCallContext) IDENTIFIER() antlr.TerminalNode {
-	return s.GetToken(NumscriptParserIDENTIFIER, 0)
-}
+func (s *FunctionCallContext) GetFnName() antlr.Token { return s.fnName }
+
+func (s *FunctionCallContext) SetFnName(v antlr.Token) { s.fnName = v }
 
 func (s *FunctionCallContext) LPARENS() antlr.TerminalNode {
 	return s.GetToken(NumscriptParserLPARENS, 0)
@@ -1439,6 +1447,14 @@ func (s *FunctionCallContext) RPARENS() antlr.TerminalNode {
 	return s.GetToken(NumscriptParserRPARENS, 0)
 }
 
+func (s *FunctionCallContext) OVERDRAFT() antlr.TerminalNode {
+	return s.GetToken(NumscriptParserOVERDRAFT, 0)
+}
+
+func (s *FunctionCallContext) IDENTIFIER() antlr.TerminalNode {
+	return s.GetToken(NumscriptParserIDENTIFIER, 0)
+}
+
 func (s *FunctionCallContext) FunctionCallArgs() IFunctionCallArgsContext {
 	var t antlr.RuleContext
 	for _, ctx := range s.GetChildren() {
@@ -1483,10 +1499,20 @@ func (p *NumscriptParser) FunctionCall() (localctx IFunctionCallContext) {
 	p.EnterOuterAlt(localctx, 1)
 	{
 		p.SetState(73)
-		p.Match(NumscriptParserIDENTIFIER)
-		if p.HasError() {
-			// Recognition error - abort rule
-			goto errorExit
+
+		var _lt = p.GetTokenStream().LT(1)
+
+		localctx.(*FunctionCallContext).fnName = _lt
+
+		_la = p.GetTokenStream().LA(1)
+
+		if !(_la == NumscriptParserOVERDRAFT || _la == NumscriptParserIDENTIFIER) {
+			var _ri = p.GetErrorHandler().RecoverInline(p)
+
+			localctx.(*FunctionCallContext).fnName = _ri
+		} else {
+			p.GetErrorHandler().ReportMatch(p)
+			p.Consume()
 		}
 	}
 	{
@@ -2164,7 +2190,7 @@ func (p *NumscriptParser) Program() (localctx IProgramContext) {
 	}
 	_la = p.GetTokenStream().LA(1)
 
-	for (int64(_la) & ^0x3f) == 0 && ((int64(1)<<_la)&8590459904) != 0 {
+	for (int64(_la) & ^0x3f) == 0 && ((int64(1)<<_la)&8590590976) != 0 {
 		{
 			p.SetState(101)
 			p.Statement()
@@ -4889,7 +4915,7 @@ func (p *NumscriptParser) Statement() (localctx IStatementContext) {
 			p.valueExpr(0)
 		}
 
-	case NumscriptParserIDENTIFIER:
+	case NumscriptParserOVERDRAFT, NumscriptParserIDENTIFIER:
 		localctx = NewFnCallStatementContext(p, localctx)
 		p.EnterOuterAlt(localctx, 3)
 		{
diff --git a/internal/parser/parser.go b/internal/parser/parser.go
index 35c4baa..a29677b 100644
--- a/internal/parser/parser.go
+++ b/internal/parser/parser.go
@@ -508,7 +508,7 @@ func parseFnCall(fnCallCtx parser.IFunctionCallContext) *FnCall {
 		return nil
 	}
 
-	ident := fnCallCtx.IDENTIFIER()
+	ident := fnCallCtx.GetFnName()
 	if ident == nil {
 		return nil
 	}
@@ -518,8 +518,8 @@ func parseFnCall(fnCallCtx parser.IFunctionCallContext) *FnCall {
 	return &FnCall{
 		Range: ctxToRange(fnCallCtx),
 		Caller: &FnCallIdentifier{
-			Range: tokenToRange(ident.GetSymbol()),
-			Name:  ident.GetSymbol().GetText(),
+			Range: tokenToRange(ident),
+			Name:  ident.GetText(),
 		},
 		Args: parseFnArgs(allArgs),
 	}