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 alpha t) a(alpha) ∈ A(alpha)) 
  supposing ∀I,J:fset(ℕ). ∀f:J ⟶ I. ∀alpha:X(I). ∀t:T(alpha).
              ((g f(alpha) (t alpha f)) (g alpha 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 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: uimplies: supposing a uall: [x:A]. B[x] all: x:A. B[x] apply: a function: x:A ⟶ B[x] equal: t ∈ T
Definitions unfolded in proof :  cubical-type-restriction: cubical-type-restriction uall: [x:A]. B[x] uimplies: supposing a all: x:A. B[x] implies:  Q member: t ∈ T squash: T prop: subtype_rel: A ⊆B true: True guard: {T} iff: ⇐⇒ Q and: P ∧ Q rev_implies:  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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