Nuprl Lemma : path-type-subtype

∀[X:j⊢]. ∀[A:{X ⊢ _}]. ∀[a,b:{X ⊢ _:A}].  ({X ⊢ _:(Path_A a b)} ⊆r {X ⊢ _:Path(A)})


Proof




Definitions occuring in Statement :  path-type: (Path_A a b),  pathtype: Path(A),  cubical-term: {X ⊢ _:A},  cubical-type: {X ⊢ _},  cubical_set: CubicalSet,  subtype_rel: A ⊆r B,  uall: ∀[x:A]. B[x]
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  subtype_rel: A ⊆r B,  cubical-term: {X ⊢ _:A},  so_lambda: λ2x.t[x],  so_apply: x[s],  uimplies: b supposing a,  all: ∀x:A. B[x],  cubical-type-ap-morph: (u a f),  pi2: snd(t),  pathtype: Path(A),  cubical-fun: (A ⟶ B),  path-type: (Path_A a b),  cubical-subset: cubical-subset
Lemmas referenced :  subtype_rel_dep_function,  I_cube_wf,  cubical-type-at_wf,  path-type_wf,  cubical_set_cumulativity-i-j,  cubical-type-cumulativity2,  pathtype_wf,  path-type-at-subtype,  fset_wf,  nat_wf,  cube-set-restriction_wf,  names-hom_wf,  istype-cubical-type-at,  cubical-type-ap-morph_wf,  cubical-term_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  lambdaEquality_alt,  sqequalHypSubstitution,  setElimination,  thin,  rename,  dependent_set_memberEquality_alt,  functionExtensionality,  applyEquality,  hypothesisEquality,  hypothesis,  instantiate,  extract_by_obid,  isectElimination,  cumulativity,  sqequalRule,  universeIsType,  because_Cache,  independent_isectElimination,  lambdaFormation_alt,  dependent_functionElimination,  inhabitedIsType,  functionIsType,  equalityIstype,  axiomEquality,  isect_memberEquality_alt,  isectIsTypeImplies

Latex:
\mforall{}[X:j\mvdash{}].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[a,b:\{X  \mvdash{}  \_:A\}].    (\{X  \mvdash{}  \_:(Path\_A  a  b)\}  \msubseteq{}r  \{X  \mvdash{}  \_:Path(A)\})



Date html generated: 2020_05_20-PM-03_14_58
Last ObjectModification: 2020_04_06-PM-05_36_40

Theory : cubical!type!theory


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