Nuprl Lemma : extend-to-contraction_wf

Gamma:j⊢. ∀A:{Gamma ⊢ _}. ∀ext:Gamma +⊢ Extension(A).
  (extend-to-contraction(Gamma;A;ext) ∈ {Gamma ⊢ _:Contractible(A)})


Proof




Definitions occuring in Statement :  extend-to-contraction: extend-to-contraction(Gamma;A;ext) uniform-extend: uniform-extend{i:l}(Gamma; A) contractible-type: Contractible(A) cubical-term: {X ⊢ _:A} cubical-type: {X ⊢ _} cubical_set: CubicalSet all: x:A. B[x] member: t ∈ T
Definitions unfolded in proof :  all: x:A. B[x] member: t ∈ T uniform-extend: uniform-extend{i:l}(Gamma; A) extension-fun: extension-fun{i:l}(Gamma;A) uall: [x:A]. B[x] subtype_rel: A ⊆B extend-to-contraction: extend-to-contraction(Gamma;A;ext) constrained-cubical-term: {Gamma ⊢ _:A[phi |⟶ t]} uimplies: supposing a so_lambda: λ2x.t[x] so_apply: x[s] cubical-type: {X ⊢ _} cc-snd: q interval-type: 𝕀 cc-fst: p csm-ap-type: (AF)s constant-cubical-type: (X) csm-comp: F compose: g csm-ap: (s)x squash: T prop: true: True uniform-extension-fun: uniform-extension-fun{i:l}(Gamma;A;ext) pi1: fst(t) csm-adjoin: (s;u) csm-id: 1(X) csm-id-adjoin: [u] interval-0: 0(𝕀) implies:  Q interval-1: 1(𝕀) csm-ap-term: (t)s pi2: snd(t) guard: {T} iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q
Lemmas referenced :  csm-ap-term_wf cube-context-adjoin_wf cubical-type-cumulativity2 cubical_set_cumulativity-i-j interval-type_wf csm-ap-type_wf cc-fst_wf cc-fst_wf_interval cc-snd_wf contr-witness_wf csm-id_wf face-0_wf empty-context-subset-lemma3 subtype_rel_set cubical-term-eqcd equal-wf-base-T thin-context-subset context-subset_wf istype-cubical-term subset-cubical-term2 sub_cubical_set_self csm-ap-id-type term-to-path_wf csm-comp_wf face-one_wf context-subset-is-subset context-subset-term-subtype path-type_wf squash_wf true_wf uniform-extend_wf cubical-type_wf cubical_set_wf csm-id-adjoin_wf-interval-0 istype-universe equal_wf csm-face-0 face-one-interval-0 csm-interval-0 cc_snd_csm_id_adjoin_lemma csm-face-one csm_id_adjoin_fst_term_lemma context-subset-map csm-id-adjoin_wf-interval-1 interval-1_wf subset-cubical-term context-1-subset face-one-interval-1 sub_cubical_set_wf face-type_wf iff_weakening_equal
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation_alt cut sqequalHypSubstitution setElimination thin rename instantiate introduction extract_by_obid isectElimination hypothesisEquality applyEquality because_Cache hypothesis sqequalRule Error :memTop,  equalityTransitivity equalitySymmetry independent_isectElimination lambdaEquality_alt baseClosed dependent_functionElimination productElimination imageElimination universeIsType inhabitedIsType natural_numberEquality imageMemberEquality hyp_replacement universeEquality applyLambdaEquality equalityIstype independent_functionElimination

Latex:
\mforall{}Gamma:j\mvdash{}.  \mforall{}A:\{Gamma  \mvdash{}  \_\}.  \mforall{}ext:Gamma  +\mvdash{}  Extension(A).
    (extend-to-contraction(Gamma;A;ext)  \mmember{}  \{Gamma  \mvdash{}  \_:Contractible(A)\})



Date html generated: 2020_05_20-PM-05_22_45
Last ObjectModification: 2020_05_02-PM-03_25_05

Theory : cubical!type!theory


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