Nuprl Lemma : discrete-pair-inv-property

[A:Type]. ∀[B:A ⟶ Type]. ∀[X:j⊢]. ∀[b:{X ⊢ _:discr(a:A × B[a])}].
  (discrete-pair(discrete-pair-inv(X;b)) b ∈ {X ⊢ _:discr(a:A × B[a])})


Proof




Definitions occuring in Statement :  discrete-pair-inv: discrete-pair-inv(X;b) discrete-pair: discrete-pair(p) discrete-cubical-type: discr(T) cubical-term: {X ⊢ _:A} cubical_set: CubicalSet uall: [x:A]. B[x] so_apply: x[s] function: x:A ⟶ B[x] product: x:A × B[x] universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T discrete-pair-inv: discrete-pair-inv(X;b) so_apply: x[s] uimplies: supposing a discrete-pair: discrete-pair(p) discrete-cubical-type: discr(T) all: x:A. B[x] cubical-snd: p.2 cubical-fst: p.1 cubical-term-at: u(a) cubical-pair: cubical-pair(u;v) pi1: fst(t) pi2: snd(t) implies:  Q
Lemmas referenced :  I_cube_wf fset_wf nat_wf cubical-term-equal discrete-cubical-type_wf cubical-term_wf cubical_set_wf istype-universe cubical_type_at_pair_lemma cubical-term-at_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt introduction cut equalitySymmetry functionExtensionality extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis productEquality applyEquality equalityTransitivity independent_isectElimination universeIsType instantiate cumulativity sqequalRule isect_memberEquality_alt axiomEquality isectIsTypeImplies inhabitedIsType functionIsType universeEquality dependent_functionElimination Error :memTop,  lambdaFormation_alt productElimination dependent_pairEquality_alt equalityIstype independent_functionElimination

Latex:
\mforall{}[A:Type].  \mforall{}[B:A  {}\mrightarrow{}  Type].  \mforall{}[X:j\mvdash{}].  \mforall{}[b:\{X  \mvdash{}  \_:discr(a:A  \mtimes{}  B[a])\}].
    (discrete-pair(discrete-pair-inv(X;b))  =  b)



Date html generated: 2020_05_20-PM-03_40_58
Last ObjectModification: 2020_04_06-PM-07_12_28

Theory : cubical!type!theory


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