Nuprl Lemma : path-restriction

[X:j⊢]. ∀[A:{X ⊢ _}]. ∀[a,b:{X ⊢ _:A}].
  cubical-type-restriction(X;Path(A);I,a1,p.((p 0) a(a1) ∈ A(a1)) ∧ ((p 1) b(a1) ∈ A(a1)))


Proof




Definitions occuring in Statement :  pathtype: Path(A) cubical-type-restriction: cubical-type-restriction cubical-term-at: u(a) cubical-term: {X ⊢ _:A} cubical-type-at: A(a) cubical-type: {X ⊢ _} cubical_set: CubicalSet nh-id: 1 dM1: 1 dM0: 0 uall: [x:A]. B[x] and: P ∧ Q apply: a equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T subtype_rel: A ⊆B so_lambda: so_lambda3 pathtype: Path(A) cubical-fun: (A ⟶ B) all: x:A. B[x] cubical-fun-family: cubical-fun-family(X; A; B; I; a) lattice-point: Point(l) record-select: r.x dM: dM(I) free-DeMorgan-algebra: free-DeMorgan-algebra(T;eq) mk-DeMorgan-algebra: mk-DeMorgan-algebra(L;n) record-update: r[x := v] ifthenelse: if then else fi  eq_atom: =a y bfalse: ff free-DeMorgan-lattice: free-DeMorgan-lattice(T;eq) free-dist-lattice: free-dist-lattice(T; eq) mk-bounded-distributive-lattice: mk-bounded-distributive-lattice mk-bounded-lattice: mk-bounded-lattice(T;m;j;z;o) btrue: tt cubical-type-at: A(a) pi1: fst(t) interval-type: 𝕀 constant-cubical-type: (X) I_cube: A(I) functor-ob: ob(F) interval-presheaf: 𝕀 so_apply: x[s1;s2;s3] implies:  Q uimplies: supposing a prop: squash: T guard: {T} iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q true: True
Lemmas referenced :  cubical-term_wf cubical-type-cumulativity2 cubical_set_cumulativity-i-j cubical-type_wf cubical_set_wf cubical-type-restriction-and pathtype_wf equal_wf cubical-type-at_wf cubical_type_at_pair_lemma nh-id_wf dM0_wf subtype_rel_self interval-type_wf cube-set-restriction_wf cubical-term-at_wf istype-cubical-type-at I_cube_wf dM1_wf cubical-type-restriction-eq names-hom_wf interval-type-at I_cube_pair_redex_lemma interval-type-ap-morph cubical_type_ap_morph_pair_lemma squash_wf true_wf istype-universe fset_wf nat_wf cube-set-restriction-id iff_weakening_equal cubical-type-ap-morph_wf subtype_rel-equal nh-id-left nh-comp_wf dM-lift_wf2 nh-id-right dM-lift-0-sq dM-lift-1-sq
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt because_Cache universeIsType cut thin instantiate introduction extract_by_obid sqequalHypSubstitution isectElimination hypothesisEquality applyEquality hypothesis sqequalRule lambdaEquality_alt dependent_functionElimination Error :memTop,  setElimination rename independent_functionElimination independent_isectElimination lambdaFormation_alt equalitySymmetry hyp_replacement imageElimination equalityTransitivity universeEquality inhabitedIsType imageMemberEquality baseClosed productElimination natural_numberEquality

Latex:
\mforall{}[X:j\mvdash{}].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[a,b:\{X  \mvdash{}  \_:A\}].
    cubical-type-restriction(X;Path(A);I,a1,p.((p  I  1  0)  =  a(a1))  \mwedge{}  ((p  I  1  1)  =  b(a1)))



Date html generated: 2020_05_20-PM-03_14_25
Last ObjectModification: 2020_04_06-PM-05_37_03

Theory : cubical!type!theory


Home Index