fact: Definition univwit (c : C) (d : D): (c ⟶ G d) → (F c ⟶ d) := φ⁻¹.
imports: MathClasses.interfaces.abstract_algebra MathClasses.theory.setoids MathClasses.interfaces.functors MathClasses.theory.categories MathClasses.misc.workaround_tactics MathClasses.theory.jections