Nuprl Lemma : ps_context-ext

∀[C:SmallCategory]
  {FM:F:cat-ob(C) ⟶ 𝕌{j'} × (I:cat-ob(C) ⟶ J:cat-ob(C) ⟶ (cat-arrow(C) J I) ⟶ (F I) ⟶ (F J))| 
   let F,M = FM 
   in (∀I:cat-ob(C). ∀s:FM(I).  (cat-id(C) I(s) = s ∈ FM(I)))
      ∧ (∀I,J,K:cat-ob(C). ∀f:cat-arrow(C) J I. ∀g:cat-arrow(C) K J. ∀s:FM(I).
           (cat-comp(C) K J I g f(s) = g(f(s)) ∈ FM(K)))}  ≡ ps_context{j:l}(C)


Proof




Definitions occuring in Statement :  psc-restriction: f(s),  I_set: A(I),  ps_context: __⊢,  ext-eq: A ≡ B,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  and: P ∧ Q,  set: {x:A| B[x]} ,  apply: f a,  function: x:A ⟶ B[x],  spread: spread def,  product: x:A × B[x],  universe: Type,  equal: s = t ∈ T,  cat-comp: cat-comp(C),  cat-id: cat-id(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,  sq_stable: SqStable(P),  implies: P ⇒ Q,  squash: ↓T,  all: ∀x:A. B[x],  and: P ∧ Q,  prop: ℙ,  subtype_rel: A ⊆r B,  small-category: SmallCategory,  spreadn: spread4,  ps_context: __⊢,  cat-arrow: cat-arrow(C),  cat-ob: cat-ob(C),  pi1: fst(t),  pi2: snd(t),  type-cat: TypeCat,  op-cat: op-cat(C),  cat-functor: Functor(C1;C2),  compose: f o g,  psc-restriction: f(s),  I_set: A(I),  functor-ob: ob(F),  ext-eq: A ≡ B,  cand: A c∧ B,  guard: {T},  true: True,  uimplies: b supposing a,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  sq_stable__ext-eq,  small-category_wf,  cat-ob_wf,  cat-arrow_wf,  I_set_pair_redex_lemma,  psc_restriction_pair_lemma,  equal_wf,  cat-id_wf,  cat-comp_wf,  ps_context_wf,  small-category-cumulativity-2,  cat_id_tuple_lemma,  cat_comp_tuple_lemma,  cat_ob_pair_lemma,  cat_arrow_triple_lemma,  istype-universe,  iff_weakening_equal,  squash_wf,  true_wf,  subtype_rel_self
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  cut,  thin,  instantiate,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesis,  independent_functionElimination,  sqequalRule,  imageMemberEquality,  hypothesisEquality,  baseClosed,  imageElimination,  universeIsType,  setEquality,  productEquality,  functionEquality,  cumulativity,  universeEquality,  applyEquality,  productElimination,  dependent_functionElimination,  Error :memTop,  setElimination,  rename,  independent_pairFormation,  lambdaEquality_alt,  setIsType,  productIsType,  functionIsType,  because_Cache,  equalityIstype,  dependent_set_memberEquality_alt,  dependent_pairEquality_alt,  inhabitedIsType,  lambdaFormation_alt,  functionExtensionality_alt,  natural_numberEquality,  equalityTransitivity,  equalitySymmetry,  independent_isectElimination

Latex:
\mforall{}[C:SmallCategory]
    \{FM:F:cat-ob(C)  {}\mrightarrow{}  \mBbbU{}\{j'\}  \mtimes{}  (I:cat-ob(C)  {}\mrightarrow{}  J:cat-ob(C)  {}\mrightarrow{}  (cat-arrow(C)  J  I)  {}\mrightarrow{}  (F  I)  {}\mrightarrow{}  (F  J))| 
      let  F,M  =  FM 
      in  (\mforall{}I:cat-ob(C).  \mforall{}s:FM(I).    (cat-id(C)  I(s)  =  s))
            \mwedge{}  (\mforall{}I,J,K:cat-ob(C).  \mforall{}f:cat-arrow(C)  J  I.  \mforall{}g:cat-arrow(C)  K  J.  \mforall{}s:FM(I).
                      (cat-comp(C)  K  J  I  g  f(s)  =  g(f(s))))\}    \mequiv{}  ps\_context\{j:l\}(C)



Date html generated: 2020_05_20-PM-01_23_22
Last ObjectModification: 2020_03_31-PM-07_30_09

Theory : presheaf!models!of!type!theory


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