Nuprl Lemma : equal-presheaves

[C:SmallCategory]. ∀[F,G:Presheaf(C)].
  G ∈ Presheaf(C) 
  supposing (∀x:cat-ob(op-cat(C)). ((F x) (G x) ∈ cat-ob(TypeCat)))
  ∧ (∀x,y:cat-ob(op-cat(C)). ∀f:cat-arrow(op-cat(C)) y.  ((F f) (G f) ∈ (cat-arrow(TypeCat) (F x) (F y))))


Proof




Definitions occuring in Statement :  presheaf: Presheaf(C) type-cat: TypeCat op-cat: op-cat(C) functor-arrow: arrow(F) functor-ob: ob(F) cat-arrow: cat-arrow(C) cat-ob: cat-ob(C) small-category: SmallCategory uimplies: supposing a uall: [x:A]. B[x] all: x:A. B[x] and: P ∧ Q apply: a equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a and: P ∧ Q presheaf: Presheaf(C) subtype_rel: A ⊆B prop: so_lambda: λ2x.t[x] so_apply: x[s] all: x:A. B[x] squash: T true: True guard: {T} iff: ⇐⇒ Q rev_implies:  Q implies:  Q
Lemmas referenced :  equal-functors op-cat_wf type-cat_wf all_wf cat-ob_wf equal_wf functor-ob_wf small-category-subtype cat-arrow_wf functor-arrow_wf subtype_rel-equal squash_wf true_wf iff_weakening_equal presheaf_wf small-category_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut sqequalHypSubstitution productElimination thin instantiate extract_by_obid isectElimination hypothesisEquality applyEquality because_Cache hypothesis sqequalRule independent_isectElimination productEquality lambdaEquality cumulativity universeEquality imageElimination equalityTransitivity equalitySymmetry dependent_functionElimination natural_numberEquality imageMemberEquality baseClosed independent_functionElimination isect_memberEquality axiomEquality

Latex:
\mforall{}[C:SmallCategory].  \mforall{}[F,G:Presheaf(C)].
    F  =  G 
    supposing  (\mforall{}x:cat-ob(op-cat(C)).  ((F  x)  =  (G  x)))
    \mwedge{}  (\mforall{}x,y:cat-ob(op-cat(C)).  \mforall{}f:cat-arrow(op-cat(C))  x  y.    ((F  x  y  f)  =  (G  x  y  f)))



Date html generated: 2020_05_20-AM-07_53_29
Last ObjectModification: 2017_10_03-PM-02_24_56

Theory : small!categories


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