fix

Author: simeonschaub

src/lambdify.jl

@@ -105,7 +105,7 @@ function walk_expression(ex; values=Dict(), fns=Dict())
     elseif fn == "Tuple"
         return walk_expression.(Introspection.args(ex), values=values, fns=fns)
     elseif fn == "Indexed"
-        return Expr(:ref, [walk_expression(a, values=values, fns=fns) for a in as]...)
+        return Expr(:ref, [walk_expression(a, values=values, fns=fns) for a in Introspection.args(ex)]...)
     elseif haskey(vals_map, fn)
         return vals_map[fn]
     end