Nuprl Lemma : discrete-fun-invariant

[A,B:Type]. ∀[f:{() ⊢ _:(discr(A) ⟶ discr(B))}]. ∀[I:fset(ℕ)]. ∀[a:()(I)].
  ((f a) (f {} ⋅) ∈ (discr(A) ⟶ discr(B))(a))


Proof




Definitions occuring in Statement :  discrete-cubical-type: discr(T) cubical-fun: (A ⟶ B) cubical-term: {X ⊢ _:A} cubical-type-at: A(a) trivial-cube-set: () I_cube: A(I) empty-fset: {} fset: fset(T) nat: it: uall: [x:A]. B[x] apply: a universe: Type equal: t ∈ T
Definitions unfolded in proof :  so_apply: x[s] so_lambda: λ2x.t[x] false: False names: names(I) names-hom: I ⟶ J cubical-fun-family: cubical-fun-family(X; A; B; I; a) top: Top all: x:A. B[x] cubical-fun: (A ⟶ B) discrete-cubical-type: discr(T) prop: trivial-cube-set: () pi1: fst(t) functor-ob: ob(F) I_cube: A(I) unit: Unit subtype_rel: A ⊆B member: t ∈ T uall: [x:A]. B[x]
Lemmas referenced :  nh-comp_wf equal_wf all_wf member-empty-fset names_wf names-hom_wf cubical_type_ap_morph_pair_lemma cubical_type_at_pair_lemma cubical-type-at_wf equal-wf-base subtype_rel_self it_wf empty-fset_wf discrete-cubical-type_wf cubical-fun_wf cubical-term_wf nat_wf fset_wf trivial-cube-set_wf I_cube_wf discrete-fun-at
Rules used in proof :  equalitySymmetry equalityTransitivity lambdaFormation functionExtensionality dependent_set_memberEquality rename setElimination voidEquality voidElimination isect_memberEquality dependent_functionElimination lambdaEquality because_Cache baseClosed intEquality sqequalRule applyEquality universeEquality cumulativity hypothesisEquality thin isectElimination sqequalHypSubstitution hypothesis isect_memberFormation sqequalReflexivity computationStep sqequalTransitivity sqequalSubstitution extract_by_obid introduction cut

Latex:
\mforall{}[A,B:Type].  \mforall{}[f:\{()  \mvdash{}  \_:(discr(A)  {}\mrightarrow{}  discr(B))\}].  \mforall{}[I:fset(\mBbbN{})].  \mforall{}[a:()(I)].    ((f  I  a)  =  (f  \{\}  \mcdot{}))



Date html generated: 2017_02_21-AM-10_43_50
Last ObjectModification: 2017_02_13-PM-03_51_29

Theory : cubical!type!theory


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