Nuprl Lemma : csm-contractible-type

[X:j⊢]. ∀[A:{X ⊢ _}]. ∀[Z:j⊢]. ∀[s:Z j⟶ X].  ((Contractible(A))s Z ⊢ Contractible((A)s) ∈ {Z ⊢ _})


Proof




Definitions occuring in Statement :  contractible-type: Contractible(A) csm-ap-type: (AF)s cubical-type: {X ⊢ _} cube_set_map: A ⟶ B cubical_set: CubicalSet uall: [x:A]. B[x] equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T subtype_rel: A ⊆B cube_set_map: A ⟶ B psc_map: A ⟶ B nat-trans: nat-trans(C;D;F;G) cat-ob: cat-ob(C) pi1: fst(t) op-cat: op-cat(C) spreadn: spread4 cube-cat: CubeCat fset: fset(T) quotient: x,y:A//B[x; y] cat-arrow: cat-arrow(C) pi2: snd(t) type-cat: TypeCat all: x:A. B[x] names-hom: I ⟶ J cat-comp: cat-comp(C) compose: g prop: squash: T true: True and: P ∧ Q uimplies: supposing a contractible-type: Contractible(A) guard: {T} iff: ⇐⇒ Q rev_implies:  Q implies:  Q cubical-type: {X ⊢ _} cc-snd: q csm-ap-type: (AF)s cc-fst: p csm-comp: F csm-ap: (s)x csm-adjoin: (s;u) csm-ap-term: (t)s
Lemmas referenced :  cube_set_map_wf cubical-type_wf cubical_set_wf csm-ap-comp-type cubical_set_cumulativity-i-j cube-context-adjoin_wf csm-ap-type_wf cubical-type-cumulativity2 cc-fst_wf subtype_rel_self equal_wf squash_wf true_wf istype-universe csm-comp_wf csm-ap-type-fst-adjoin subtype_rel-equal csm-cubical-sigma cubical-pi_wf path-type_wf csm-ap-term_wf cc-snd_wf cubical-sigma_wf iff_weakening_equal csm-cubical-pi csm-adjoin_wf csm-adjoin-comp csm-comp-type cubical-term_wf csm-path-type csm-ap-term-snd-adjoin
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt introduction cut hypothesis universeIsType extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality sqequalRule isect_memberEquality_alt axiomEquality isectIsTypeImplies inhabitedIsType instantiate applyEquality because_Cache applyLambdaEquality equalitySymmetry hyp_replacement lambdaEquality_alt imageElimination equalityTransitivity universeEquality natural_numberEquality imageMemberEquality baseClosed Error :memTop,  dependent_set_memberEquality_alt independent_pairFormation productIsType equalityIstype setElimination rename productElimination independent_isectElimination dependent_functionElimination independent_functionElimination

Latex:
\mforall{}[X:j\mvdash{}].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[Z:j\mvdash{}].  \mforall{}[s:Z  j{}\mrightarrow{}  X].    ((Contractible(A))s  =  Z  \mvdash{}  Contractible((A)s))



Date html generated: 2020_05_20-PM-03_22_52
Last ObjectModification: 2020_04_07-PM-05_05_19

Theory : cubical!type!theory


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