Nuprl Lemma : path-restriction

∀[X:j⊢]. ∀[A:{X ⊢ _}]. ∀[a,b:{X ⊢ _:A}].
  cubical-type-restriction(X;Path(A);I,a1,p.((p I 1 0) = a(a1) ∈ A(a1)) ∧ ((p I 1 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: f a,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  subtype_rel: A ⊆r 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 b then t else f fi ,  eq_atom: x =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: P ⇒ Q,  uimplies: b supposing a,  prop: ℙ,  squash: ↓T,  guard: {T},  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ 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


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