Nuprl Lemma : equal-functors
∀[A,B:SmallCategory]. ∀[F,G:Functor(A;B)].
  (F = G ∈ Functor(A;B)) supposing 
     ((∀x,y:cat-ob(A). ∀f:cat-arrow(A) x y.  ((F x y f) = (G x y f) ∈ (cat-arrow(B) (F x) (F y)))) and 
     (∀x:cat-ob(A). ((F x) = (G x) ∈ cat-ob(B))))
Proof
Definitions occuring in Statement : 
functor-arrow: arrow(F), 
functor-ob: ob(F), 
cat-functor: Functor(C1;C2), 
cat-arrow: cat-arrow(C), 
cat-ob: cat-ob(C), 
small-category: SmallCategory, 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
apply: f a, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
uimplies: b supposing a, 
cat-functor: Functor(C1;C2), 
and: P ∧ Q, 
all: ∀x:A. B[x], 
top: Top, 
squash: ↓T, 
true: True, 
subtype_rel: A ⊆r B, 
prop: ℙ, 
guard: {T}, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q, 
implies: P ⇒ Q, 
cand: A c∧ B, 
so_lambda: λ2x.t[x], 
so_apply: x[s]
Lemmas referenced : 
ob_pair_lemma, 
arrow_pair_lemma, 
equal_wf, 
cat-ob_wf, 
iff_weakening_equal, 
cat-arrow_wf, 
all_wf, 
cat-id_wf, 
cat-comp_wf, 
functor-ob_wf, 
functor-arrow_wf, 
subtype_rel-equal, 
squash_wf, 
true_wf, 
cat-functor_wf, 
small-category_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalHypSubstitution, 
setElimination, 
thin, 
rename, 
productElimination, 
sqequalRule, 
extract_by_obid, 
dependent_functionElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
hypothesis, 
dependent_set_memberEquality, 
dependent_pairEquality, 
functionExtensionality, 
applyEquality, 
lambdaEquality, 
imageElimination, 
isectElimination, 
because_Cache, 
hypothesisEquality, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
universeEquality, 
equalityTransitivity, 
equalitySymmetry, 
independent_isectElimination, 
independent_functionElimination, 
functionEquality, 
independent_pairFormation, 
productEquality, 
instantiate, 
axiomEquality
Latex:
\mforall{}[A,B:SmallCategory].  \mforall{}[F,G:Functor(A;B)].
    (F  =  G)  supposing 
          ((\mforall{}x,y:cat-ob(A).  \mforall{}f:cat-arrow(A)  x  y.    ((F  x  y  f)  =  (G  x  y  f)))  and 
          (\mforall{}x:cat-ob(A).  ((F  x)  =  (G  x))))
Date html generated:
2020_05_20-AM-07_53_26
Last ObjectModification:
2017_07_28-AM-09_19_41
Theory : small!categories
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