Nuprl Lemma : path-type-subtype

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


Proof




Definitions occuring in Statement :  path-type: (Path_A b) pathtype: Path(A) cubical-term: {X ⊢ _:A} cubical-type: {X ⊢ _} cubical_set: CubicalSet subtype_rel: A ⊆B uall: [x:A]. B[x]
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T subtype_rel: A ⊆B cubical-term: {X ⊢ _:A} so_lambda: λ2x.t[x] so_apply: x[s] uimplies: supposing a all: x:A. B[x] cubical-type-ap-morph: (u f) pi2: snd(t) pathtype: Path(A) cubical-fun: (A ⟶ B) path-type: (Path_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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