Nuprl Lemma : presheaf-type-ap-morph-comp-eq

[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A:{X ⊢ _}]. ∀[I,J,K:cat-ob(C)]. ∀[f:cat-arrow(C) I].
[g:cat-arrow(C) J]. ∀[a:X(I)]. ∀[b:X(J)]. ∀[u:A(a)].
  ((u f) g) (u cat-comp(C) f) ∈ A(cat-comp(C) f(a)) supposing f(a) ∈ X(J)


Proof




Definitions occuring in Statement :  presheaf-type-ap-morph: (u f) presheaf-type-at: A(a) presheaf-type: {X ⊢ _} psc-restriction: f(s) I_set: A(I) ps_context: __⊢ uimplies: supposing a uall: [x:A]. B[x] apply: a equal: t ∈ T cat-comp: cat-comp(C) cat-arrow: cat-arrow(C) cat-ob: cat-ob(C) small-category: SmallCategory
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a subtype_rel: A ⊆B and: P ∧ Q prop: squash: T true: True all: x:A. B[x]
Lemmas referenced :  psc-restriction_wf ps_context_cumulativity2 small-category-cumulativity-2 presheaf-type-at_wf I_set_wf cat-arrow_wf presheaf-type-ap-morph-comp equal_wf cat-comp_wf presheaf-type-ap-morph_wf subtype_rel-equal psc-restriction-comp
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt introduction cut hypothesis equalityIstype inhabitedIsType hypothesisEquality thin instantiate extract_by_obid sqequalHypSubstitution isectElimination applyEquality because_Cache sqequalRule isect_memberEquality_alt axiomEquality isectIsTypeImplies universeIsType dependent_set_memberEquality_alt independent_pairFormation equalityTransitivity equalitySymmetry productIsType hyp_replacement applyLambdaEquality setElimination rename productElimination lambdaEquality_alt imageElimination natural_numberEquality imageMemberEquality baseClosed independent_isectElimination dependent_functionElimination

Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X:ps\_context\{j:l\}(C)].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[I,J,K:cat-ob(C)].
\mforall{}[f:cat-arrow(C)  J  I].  \mforall{}[g:cat-arrow(C)  K  J].  \mforall{}[a:X(I)].  \mforall{}[b:X(J)].  \mforall{}[u:A(a)].
    ((u  a  f)  b  g)  =  (u  a  cat-comp(C)  K  J  I  g  f)  supposing  b  =  f(a)



Date html generated: 2020_05_20-PM-01_26_01
Last ObjectModification: 2020_04_01-PM-00_01_23

Theory : presheaf!models!of!type!theory


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