Added other features to the logic module.
Added other features to the logic module.

simplify and solver were added
fixed a minor bug that denied operations with more than one symbol

bolshoibooze/sympy_gamma,debugger22/sympy_gamma,bolshoibooze/sympy_gamma,bolshoibooze/sympy_gamma,iScienceLuvr/sympy_gamma,github4ry/sympy_gamma,github4ry/sympy_gamma,kaichogami/sympy_gamma,iScienceLuvr/sympy_gamma,kaichogami/sympy_gamma,iScienceLuvr/sympy_gamma,github4ry/sympy_gamma,debugger22/sympy_gamma,kaichogami/sympy_gamma