prepend 'gradient' with 'Symbolics.'

src/Initialization/init_Symbolics.jl

@@ -1,5 +1,4 @@
-using .Symbolics: gradient,
-                  simplify,
+using .Symbolics: simplify,
                   Num,  # variable like, e.g. x[1]
                   Term, # term like, eg. x[1] + x[2] == 1
                   Symbolic,

src/Sets/HPolyhedron/HPolyhedron.jl

@@ -111,7 +111,7 @@ function load_symbolics_hpolyhedron()
                     end
                 end
 
-                coeffs = [N(α.val) for α in gradient(sexpr, vars_list)]
+                coeffs = [N(α.val) for α in Symbolics.gradient(sexpr, vars_list)]
                 β = -N(Symbolics.substitute(sexpr, zeroed_vars))
 
                 push!(clist, HalfSpace(coeffs, β))

src/Sets/HalfSpace.jl

@@ -627,7 +627,7 @@ function load_symbolics_halfspace()
             end
 
             # compute the linear coefficients by taking first-order derivatives
-            coeffs = [N(α.val) for α in gradient(sexpr, collect(vars))]
+            coeffs = [N(α.val) for α in Symbolics.gradient(sexpr, collect(vars))]
 
             # get the constant term by expression substitution
             zeroed_vars = Dict(v => zero(N) for v in vars)

src/Sets/Hyperplane.jl

@@ -596,7 +596,7 @@ function load_symbolics_hyperplane()
             end
 
             # compute the linear coefficients by taking first order derivatives
-            coeffs = [N(α.val) for α in gradient(sexpr, collect(vars))]
+            coeffs = [N(α.val) for α in Symbolics.gradient(sexpr, collect(vars))]
 
             # get the constant term by expression substitution
             zeroed_vars = Dict(v => zero(N) for v in vars)