Nuprl Lemma : psc-restriction-comp2

∀C:SmallCategory. ∀X:ps_context{j:l}(C). ∀I,J1,J2,K:cat-ob(C). ∀f:cat-arrow(C) J1 I. ∀g:cat-arrow(C) K J1. ∀a:X(I).
  g(f(a)) = cat-comp(C) K J1 I g f(a) ∈ X(K) supposing J1 = J2 ∈ cat-ob(C)


Proof




Definitions occuring in Statement :  psc-restriction: f(s),  I_set: A(I),  ps_context: __⊢,  uimplies: b supposing a,  all: ∀x:A. B[x],  apply: f a,  equal: s = t ∈ T,  cat-comp: cat-comp(C),  cat-arrow: cat-arrow(C),  cat-ob: cat-ob(C),  small-category: SmallCategory
Definitions unfolded in proof :  all: ∀x:A. B[x],  uimplies: b supposing a,  member: t ∈ T,  squash: ↓T,  uall: ∀[x:A]. B[x],  subtype_rel: A ⊆r B,  and: P ∧ Q,  true: True,  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q
Lemmas referenced :  equal_wf,  I_set_wf,  psc-restriction_wf,  small-category-cumulativity-2,  ps_context_cumulativity2,  subtype_rel-equal,  cat-arrow_wf,  cat-comp_wf,  iff_weakening_equal,  psc-restriction-comp
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  isect_memberFormation_alt,  cut,  applyEquality,  thin,  instantiate,  lambdaEquality_alt,  sqequalHypSubstitution,  imageElimination,  introduction,  extract_by_obid,  isectElimination,  because_Cache,  hypothesis,  hypothesisEquality,  sqequalRule,  independent_isectElimination,  equalitySymmetry,  dependent_set_memberEquality_alt,  independent_pairFormation,  equalityTransitivity,  productIsType,  equalityIstype,  inhabitedIsType,  applyLambdaEquality,  setElimination,  rename,  productElimination,  natural_numberEquality,  imageMemberEquality,  baseClosed,  independent_functionElimination,  dependent_functionElimination,  universeIsType

Latex:
\mforall{}C:SmallCategory.  \mforall{}X:ps\_context\{j:l\}(C).  \mforall{}I,J1,J2,K:cat-ob(C).  \mforall{}f:cat-arrow(C)  J1  I.
\mforall{}g:cat-arrow(C)  K  J1.  \mforall{}a:X(I).
    g(f(a))  =  cat-comp(C)  K  J1  I  g  f(a)  supposing  J1  =  J2



Date html generated: 2020_05_20-PM-01_24_33
Last ObjectModification: 2020_04_01-AM-11_00_38

Theory : presheaf!models!of!type!theory


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