Nuprl Lemma : path-type-ext-eq

[X:j⊢]. ∀[A:{X ⊢ _}]. ∀[a,b:{X ⊢ _:A}].
  {t:{X ⊢ _:Path(A)}| (t 0(𝕀a ∈ {X ⊢ _:A}) ∧ (t 1(𝕀b ∈ {X ⊢ _:A})}  ≡ {X ⊢ _:(Path_A b)}


Proof




Definitions occuring in Statement :  path-type: (Path_A b) cubicalpath-app: pth r pathtype: Path(A) interval-1: 1(𝕀) interval-0: 0(𝕀) cubical-term: {X ⊢ _:A} cubical-type: {X ⊢ _} cubical_set: CubicalSet ext-eq: A ≡ B uall: [x:A]. B[x] and: P ∧ Q set: {x:A| B[x]}  equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T ext-eq: A ≡ B and: P ∧ Q subtype_rel: A ⊆B cubical-term: {X ⊢ _:A} path-type: (Path_A b) cubical-subset: cubical-subset all: x:A. B[x] cand: c∧ B pathtype: Path(A) cubical-fun: (A ⟶ B) cubical-fun-family: cubical-fun-family(X; A; B; I; a) uimplies: supposing a squash: T true: True respects-equality: respects-equality(S;T) implies:  Q prop: interval-0: 0(𝕀) cubicalpath-app: pth r cubical-term-at: u(a) cubical-app: app(w; u) interval-1: 1(𝕀) guard: {T} 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 cubical-path-app: pth r
Lemmas referenced :  cubical-term_wf pathtype_wf cubical-type-cumulativity2 cubical_set_cumulativity-i-j cubicalpath-app_wf interval-0_wf interval-1_wf path-type_wf cubical-type_wf cubical_set_wf cubical_type_at_pair_lemma I_cube_wf fset_wf nat_wf cubical_type_ap_morph_pair_lemma names-hom_wf istype-cubical-type-at cube-set-restriction_wf cubical-type-ap-morph_wf nh-id_wf dM0_wf cubical-term-at_wf subtype-respects-equality cubical-type-at_wf subtype_rel-equal cube-set-restriction-id dM1_wf squash_wf true_wf equal_wf istype-universe subtype_rel_self interval-type_wf path-type-subtype cubical-path-app-0 cubical-path-app-1
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt introduction cut independent_pairFormation lambdaEquality_alt setIsType universeIsType thin instantiate extract_by_obid sqequalHypSubstitution isectElimination hypothesisEquality applyEquality hypothesis sqequalRule productIsType equalityIstype because_Cache productElimination independent_pairEquality axiomEquality inhabitedIsType isect_memberEquality_alt isectIsTypeImplies setElimination rename dependent_set_memberEquality_alt dependent_functionElimination Error :memTop,  functionExtensionality lambdaFormation_alt functionIsType independent_isectElimination imageElimination natural_numberEquality imageMemberEquality baseClosed independent_functionElimination equalityTransitivity equalitySymmetry hyp_replacement universeEquality applyLambdaEquality

Latex:
\mforall{}[X:j\mvdash{}].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[a,b:\{X  \mvdash{}  \_:A\}].
    \{t:\{X  \mvdash{}  \_:Path(A)\}|  (t  @  0(\mBbbI{})  =  a)  \mwedge{}  (t  @  1(\mBbbI{})  =  b)\}    \mequiv{}  \{X  \mvdash{}  \_:(Path\_A  a  b)\}



Date html generated: 2020_05_20-PM-03_17_17
Last ObjectModification: 2020_04_06-PM-06_36_07

Theory : cubical!type!theory


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