Nuprl Lemma : discrete-fun-at

[A,B:Type]. ∀[f:{() ⊢ _:(discr(A) ⟶ discr(B))}]. ∀[I:fset(ℕ)]. ∀[a:()(I)].
  ((f a) J,h,u. (f {} ⋅ {} u)) ∈ (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) nh-id: 1 empty-fset: {} fset: fset(T) nat: it: uall: [x:A]. B[x] apply: a lambda: λx.A[x] universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T discrete-cubical-type: discr(T) cubical-fun: (A ⟶ B) cubical-fun-family: cubical-fun-family(X; A; B; I; a) all: x:A. B[x] top: Top cubical-term: {X ⊢ _:A} cubical-type-at: A(a) pi1: fst(t) so_lambda: λ2x.t[x] so_apply: x[s] prop: trivial-cube-set: () cubical-type-ap-morph: (u f) pi2: snd(t) subtype_rel: A ⊆B I_cube: A(I) functor-ob: ob(F) unit: Unit squash: T true: True uimplies: supposing a guard: {T} iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q implies:  Q names-hom: I ⟶ J names: names(I) false: False nh-id: 1 nh-comp: g ⋅ f dma-lift-compose: dma-lift-compose(I;J;eqi;eqj;f;g) compose: g dM: dM(I) dM-lift: dM-lift(I;J;f)
Lemmas referenced :  I_cube_wf fset_wf nat_wf cubical-term_wf trivial-cube-set_wf cubical-fun_wf discrete-cubical-type_wf cubical_type_at_pair_lemma cubical_type_ap_morph_pair_lemma names-hom_wf all_wf equal_wf nh-comp_wf I_cube_pair_redex_lemma cube_set_restriction_pair_lemma subtype_rel_self equal-wf-base nh-id_wf squash_wf true_wf nh-id-left iff_weakening_equal empty-fset_wf dM0_wf names_wf it_wf member-empty-fset dM-lift-0-sq set_wf nh-id-right
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation cut introduction extract_by_obid sqequalHypSubstitution isectElimination thin because_Cache hypothesisEquality hypothesis cumulativity universeEquality promote_hyp sqequalRule dependent_functionElimination isect_memberEquality voidElimination voidEquality setElimination rename dependent_set_memberEquality lambdaFormation lambdaEquality applyEquality functionExtensionality intEquality baseClosed applyLambdaEquality hyp_replacement equalitySymmetry imageElimination equalityTransitivity natural_numberEquality imageMemberEquality setEquality independent_isectElimination productElimination independent_functionElimination functionEquality

Latex:
\mforall{}[A,B:Type].  \mforall{}[f:\{()  \mvdash{}  \_:(discr(A)  {}\mrightarrow{}  discr(B))\}].  \mforall{}[I:fset(\mBbbN{})].  \mforall{}[a:()(I)].
    ((f  I  a)  =  (\mlambda{}J,h,u.  (f  \{\}  \mcdot{}  \{\}  1  u)))



Date html generated: 2017_10_05-AM-02_12_05
Last ObjectModification: 2017_03_02-PM-11_21_53

Theory : cubical!type!theory


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