Fix test that used sympy antipattern
calling a symbol which resulted in a Function was introduced as a workaround for sympy internals and these were fixed in sympy 1.3 and calling a symbol was removed.
Fixes #8 (closed)
calling a symbol which resulted in a Function was introduced as a workaround for sympy internals and these were fixed in sympy 1.3 and calling a symbol was removed.
Fixes #8 (closed)