Nuprl Lemma : psc-restriction-comp

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


Proof




Definitions occuring in Statement :  psc-restriction: f(s),  I_set: A(I),  ps_context: __⊢,  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],  member: t ∈ T,  ps_context: __⊢,  cat-functor: Functor(C1;C2),  and: P ∧ Q,  psc-restriction: f(s),  pi2: snd(t),  small-category: SmallCategory,  spreadn: spread4,  cat-arrow: cat-arrow(C),  pi1: fst(t),  cat-ob: cat-ob(C),  type-cat: TypeCat,  cat-comp: cat-comp(C),  op-cat: op-cat(C),  cat-id: cat-id(C),  squash: ↓T,  uall: ∀[x:A]. B[x],  prop: ℙ,  I_set: A(I),  true: True,  subtype_rel: A ⊆r B,  uimplies: b supposing a,  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q,  compose: f o g
Lemmas referenced :  I_set_pair_redex_lemma,  equal_wf,  squash_wf,  true_wf,  istype-universe,  ob_pair_lemma,  subtype_rel_self,  iff_weakening_equal,  compose_wf,  I_set_wf,  cat-arrow_wf,  cat-ob_wf,  ps_context_wf,  small-category-cumulativity-2
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  cut,  hypothesisEquality,  sqequalHypSubstitution,  setElimination,  thin,  rename,  productElimination,  sqequalRule,  introduction,  extract_by_obid,  dependent_functionElimination,  Error :memTop,  hypothesis,  applyEquality,  instantiate,  lambdaEquality_alt,  imageElimination,  isectElimination,  equalityTransitivity,  equalitySymmetry,  universeIsType,  universeEquality,  because_Cache,  natural_numberEquality,  imageMemberEquality,  baseClosed,  independent_isectElimination,  independent_functionElimination,  inhabitedIsType

Latex:
\mforall{}C:SmallCategory.  \mforall{}X:ps\_context\{j:l\}(C).  \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).
    (g(f(a))  =  cat-comp(C)  K  J  I  g  f(a))



Date html generated: 2020_05_20-PM-01_24_30
Last ObjectModification: 2020_04_01-AM-11_00_37

Theory : presheaf!models!of!type!theory


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