Nuprl Lemma : cubical-type-restriction-eq

∀[X:j⊢]. ∀[T,A:{X ⊢ _}]. ∀[a:{X ⊢ _:A}]. ∀[g:I:fset(ℕ) ⟶ alpha:X(I) ⟶ T(alpha) ⟶ A(alpha)].
  cubical-type-restriction(X;T;I,alpha,t.(g I alpha t) = a(alpha) ∈ A(alpha)) 
  supposing ∀I,J:fset(ℕ). ∀f:J ⟶ I. ∀alpha:X(I). ∀t:T(alpha).
              ((g J f(alpha) (t alpha f)) = (g I alpha t alpha f) ∈ A(f(alpha)))


Proof




Definitions occuring in Statement :  cubical-type-restriction: cubical-type-restriction,  cubical-term-at: u(a),  cubical-term: {X ⊢ _:A},  cubical-type-ap-morph: (u a f),  cubical-type-at: A(a),  cubical-type: {X ⊢ _},  cube-set-restriction: f(s),  I_cube: A(I),  cubical_set: CubicalSet,  names-hom: I ⟶ J,  fset: fset(T),  nat: ℕ,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  apply: f a,  function: x:A ⟶ B[x],  equal: s = t ∈ T
Definitions unfolded in proof :  cubical-type-restriction: cubical-type-restriction,  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  squash: ↓T,  prop: ℙ,  subtype_rel: A ⊆r B,  true: True,  guard: {T},  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  equal_wf,  squash_wf,  true_wf,  istype-universe,  cubical-type-at_wf,  cube-set-restriction_wf,  cubical-type-ap-morph_wf,  cubical-type-cumulativity2,  cubical_set_cumulativity-i-j,  cubical-term-at-morph,  subtype_rel_self,  iff_weakening_equal,  istype-cubical-type-at,  cubical-term-at_wf,  I_cube_wf,  names-hom_wf,  fset_wf,  nat_wf,  cubical-term_wf,  cubical-type_wf,  cubical_set_wf
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  isect_memberFormation_alt,  lambdaFormation_alt,  cut,  applyEquality,  thin,  lambdaEquality_alt,  sqequalHypSubstitution,  imageElimination,  introduction,  extract_by_obid,  isectElimination,  hypothesisEquality,  equalityTransitivity,  hypothesis,  equalitySymmetry,  universeIsType,  instantiate,  universeEquality,  because_Cache,  natural_numberEquality,  imageMemberEquality,  baseClosed,  independent_isectElimination,  productElimination,  independent_functionElimination,  equalityIstype,  functionIsType,  inhabitedIsType,  dependent_functionElimination

Latex:
\mforall{}[X:j\mvdash{}].  \mforall{}[T,A:\{X  \mvdash{}  \_\}].  \mforall{}[a:\{X  \mvdash{}  \_:A\}].  \mforall{}[g:I:fset(\mBbbN{})  {}\mrightarrow{}  alpha:X(I)  {}\mrightarrow{}  T(alpha)  {}\mrightarrow{}  A(alpha)].
    cubical-type-restriction(X;T;I,alpha,t.(g  I  alpha  t)  =  a(alpha)) 
    supposing  \mforall{}I,J:fset(\mBbbN{}).  \mforall{}f:J  {}\mrightarrow{}  I.  \mforall{}alpha:X(I).  \mforall{}t:T(alpha).
                            ((g  J  f(alpha)  (t  alpha  f))  =  (g  I  alpha  t  alpha  f))



Date html generated: 2020_05_20-PM-03_13_23
Last ObjectModification: 2020_04_06-PM-05_16_51

Theory : cubical!type!theory


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