'Since function is an implication, return its consequent.  There should be
no need to check that the application is valid since the checking is done
by the constructor.
:param bindings: ``BindingDict`` A dictionary of bindings used to simplify
:return: ``Expression``'

def simplify(self, bindings=None):

    if (not bindings):
        bindings = self.bindings
    return self.function.simplify(bindings).consequent
