import proveit from proveit import Lambda, Conditional from proveit import x, fx, gx, Qx from proveit.logic import Equals, Forall %begin demonstrations
universal_eq = Forall(x, Equals(fx, gx))
Lambda(x, fx).substitution(universal_eq, assumptions=[universal_eq])
universal_eq_with_cond = Forall(x, Equals(fx, gx), condition=Qx)
Lambda(x, Conditional(fx, Qx)).substitution(universal_eq_with_cond, assumptions=[universal_eq_with_cond])
%end demonstrations