Nuprl Lemma : equiv-path1-constraint

[G:j⊢]. ∀[A,B:{G ⊢ _}]. ∀[f:{G ⊢ _:Equiv(A;B)}].
  G.𝕀((q=0) ∨ (q=1)) ⊢ equiv-path1(G;A;B;f) (if (q=0) then (A)p else (B)p)


Proof




Definitions occuring in Statement :  equiv-path1: equiv-path1(G;A;B;f) cubical-equiv: Equiv(T;A) case-type: (if phi then else B) same-cubical-type: Gamma ⊢ B context-subset: Gamma, phi face-zero: (i=0) face-one: (i=1) face-or: (a ∨ b) interval-type: 𝕀 cc-snd: q cc-fst: p cube-context-adjoin: X.A cubical-term: {X ⊢ _:A} csm-ap-type: (AF)s cubical-type: {X ⊢ _} cubical_set: CubicalSet uall: [x:A]. B[x]
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] member: t ∈ T subtype_rel: A ⊆B uimplies: supposing a cc-snd: q interval-type: 𝕀 cc-fst: p csm-ap-type: (AF)s constant-cubical-type: (X) guard: {T} equiv-path1: equiv-path1(G;A;B;f)
Lemmas referenced :  csm-ap-type_wf cube-context-adjoin_wf interval-type_wf cc-fst_wf_interval subset-cubical-type context-subset_wf context-subset-is-subset istype-cubical-term face-type_wf glue-type-constraint face-or_wf face-zero_wf cc-snd_wf face-one_wf case-type_wf same-cubical-type-zero-and-one face-0_wf equiv-fun_wf cubical-equiv-by-cases_wf cubical-equiv_wf cubical-type_wf cubical_set_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt cut lambdaFormation_alt introduction extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality instantiate hypothesis applyEquality because_Cache independent_isectElimination sqequalRule equalityTransitivity equalitySymmetry dependent_functionElimination universeIsType

Latex:
\mforall{}[G:j\mvdash{}].  \mforall{}[A,B:\{G  \mvdash{}  \_\}].  \mforall{}[f:\{G  \mvdash{}  \_:Equiv(A;B)\}].
    G.\mBbbI{},  ((q=0)  \mvee{}  (q=1))  \mvdash{}  equiv-path1(G;A;B;f)  =  (if  (q=0)  then  (A)p  else  (B)p)



Date html generated: 2020_05_20-PM-07_26_49
Last ObjectModification: 2020_04_25-PM-10_13_05

Theory : cubical!type!theory


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