diff --git a/LICENSE.txt b/LICENSE.txt
index 8f3f847..6eb5ffb 100644
--- a/LICENSE.txt
+++ b/LICENSE.txt
@@ -1,6 +1,6 @@
BSD 3-Clause License
-Copyright (c) 2021-2023, Alexander Steen
+Copyright (c) 2021-2024, Alexander Steen
All rights reserved.
Redistribution and use in source and binary forms, with or without
diff --git a/README.md b/README.md
index c15fdba..af74132 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,8 @@ logic-embedding
_A tool for embedding non-classical logics into higher-order logic (HOL)_
The tool translates a TPTP problem statement formulated in a non-classical logic
-(using the logic specification format) into monomorphic or polymorphic THF.
+(using the logic specification format) into classical higher-order logic
+(THF format) or first-order logic (TFF format), either using monomorphic or polymorphic types.
A description of the tool is available as tool paper [^2], the underlying TPTP syntax is
described in [^3].
@@ -36,8 +37,9 @@ problem, suitable parameters are given as properties to the logic specification:
|-------------------|--------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `$modal` | `$domains` | Selects whether quantification semantics is varying domains, constant domains, cumulative domains or decreasing domains.
Accepted values: `$varying`, `$constant`, `$cumulative`, `$decreasing` |
| | `$designation` | Selects whether non-logical symbols (constants and function symbols) have rigid or flexible designation (i.e., the same interpretation in all worlds, or possibly different ones in different worlds).
Accepted values: `$rigid`, `$flexible` |
+| | `$terms` | Selects whether terms, in each world `w`, are interpreted as elements from the respective domain at `w` (i.e., whether they exist in that world); this case is referred to as local terms. With global terms, terms may be interpreted as elements from arbitrary worlds (i.e., in particular, the interpretation of a term at a specific world may not exist exist at that world).
Accepted values: `$local`, `$global` |
| | `$modalities` | Selects the properties for the modal operators.
Accepted values, for each modality: `$modal_system_X` where `X` ∈ {`K`, `KB`, `K4`, `K5`, `K45`, `KB5`, `D`, `DB`, `D4`, `D5`, `D45`, `T`, `B`, `S4`, `S5`, `S5U`}
_or a list of axiom schemes_
[`$modal axiom X1` , ..., `$modal axiom Xn` ] `Xi` ∈ {`K`, `T`, `B`, `D`, `4`, `5`, `CD`, `C4`} |
-| `$$hybrid` | _same as `$modal`_ | |
+| `$$hybrid` | _same as `$modal`_ (except that `$terms` is not available, yet). | |
| `$$pal` | _none_ | |
| `$$ddl` | `$$system` | Selects which DDL logic system is employed: Carmo and Jones or Åqvist's system E.
Accepted values: `$$carmoJones` or `$$aqvistE` |
| `$$normative` | `$logic` | Selects which deontic logic system should be used for compiling the semantically underspecified statements into concrete expressions.
Accepted values: `$$sdl` for SDL, `$$carmoJones` for the DDL of Carmo and Jones, `$$aqvistE` for Aqvist's DDL E | |
@@ -52,6 +54,7 @@ modal logic model is non-cumulative.
tff(modal_k5, logic, $modal == [
$designation == $rigid,
$domains == $decreasing,
+ $terms == $local,
$modalities == [$modal_axiom_K, $modal_axiom_5]
] ).
@@ -108,6 +111,7 @@ thf(advanced,logic,(
$modal ==
[ $designation == $rigid,
$domains == $cumulative,
+ $terms == $global,
$modalities ==
[ $modal_system_S5,
{$box(#a)} == $modal_system_KB,
@@ -125,6 +129,7 @@ thf(quantification,logic,(
$domains ==
[ $constant,
human_type == $varying ],
+ $terms == $global,
$modalities == $modal_system_S5 ] )).
```
Here, every quantification over variables of type `human_type` are varying domain, all others constant domain.
@@ -138,6 +143,7 @@ tff(modal_system,logic,
$modal ==
[ $designation == $rigid,
$domains == $cumulative,
+ $terms == $local,
$modalities == [
{$box(#always)} == $modal_system_S4,
{$box(#load)} == $modal_system_K,