Nuprl Lemma : discrete-sigma-equiv

A:Type. ∀B:A ⟶ Type. ∀X:j⊢.  {X ⊢ _:Equiv(Σ discr(A) discrete-family(A;a.B[a]);discr(a:A × B[a]))}


Proof




Definitions occuring in Statement :  discrete-family: discrete-family(A;a.B[a]) cubical-equiv: Equiv(T;A) discrete-cubical-type: discr(T) cubical-sigma: Σ B cubical-term: {X ⊢ _:A} cubical_set: CubicalSet so_apply: x[s] all: x:A. B[x] function: x:A ⟶ B[x] product: x:A × B[x] universe: Type
Definitions unfolded in proof :  all: x:A. B[x] member: t ∈ T uall: [x:A]. B[x] so_lambda: λ2x.t[x] so_apply: x[s] discrete-family: discrete-family(A;a.B[a]) cc-snd: q cc-fst: p csm-comp: F csm-adjoin: (s;u) csm-ap-type: (AF)s compose: g csm-ap: (s)x pi2: snd(t) subtype_rel: A ⊆B uimplies: supposing a squash: T prop: true: True discrete-cubical-type: discr(T) cubical-lam: cubical-lam(X;b) cubical-app: app(w; u) cubical-lambda: b) cube-context-adjoin: X.A discrete-pair-inv: discrete-pair-inv(X;b) discrete-pair: discrete-pair(p) cubical-pair: cubical-pair(u;v) cubical-snd: p.2 cubical-fst: p.1 cubical-term-at: u(a) cc-adjoin-cube: (v;u) csm-ap-term: (t)s pi1: fst(t) implies:  Q and: P ∧ Q iff: ⇐⇒ Q rev_implies:  Q fiber-member: fiber-member(p) fiber-point: fiber-point(t;c)
Lemmas referenced :  cubical_set_wf istype-universe cubical-sigma-p cubical-sigma_wf discrete-cubical-type_wf discrete-family_wf csm-discrete-cubical-type discrete-pair_wf cube-context-adjoin_wf cubical_set_cumulativity-i-j cubical-type-cumulativity2 cc-snd_wf csm-discrete-family cubical-term-eqcd discrete-pair-inv_wf csm-discrete-sigma cc-fst_wf path-type_wf squash_wf true_wf istype-cubical-term cubical-type_wf csm-ap-type_wf cubical-refl_wf I_cube_wf fset_wf nat_wf cubical-term-equal cubical_type_at_pair_lemma I_cube_pair_redex_lemma cubical-fiber_wf csm-ap-term_wf cubical-fun_wf cubical-lam_wf csm-cubical-fun csm-cubical-fiber equal-fiber-discrete fiber-point_wf csm-fiber-point fiber-discrete-equal fiber-member_wf equal_wf discrete-pair-injection cubical-term_wf cubical-term-at_wf discrete-pair-inv-property cubical-fst-pair equiv-witness_wf cubical-lambda_wf contractible-type_wf contr-witness_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation_alt cut universeIsType thin instantiate introduction extract_by_obid hypothesis functionIsType hypothesisEquality inhabitedIsType sqequalHypSubstitution isectElimination universeEquality dependent_functionElimination sqequalRule lambdaEquality_alt applyEquality Error :memTop,  because_Cache equalityTransitivity equalitySymmetry independent_isectElimination hyp_replacement cumulativity productEquality imageElimination natural_numberEquality imageMemberEquality baseClosed functionExtensionality productElimination dependent_pairEquality_alt equalityIstype independent_functionElimination dependent_set_memberEquality_alt independent_pairFormation productIsType applyLambdaEquality setElimination rename

Latex:
\mforall{}A:Type.  \mforall{}B:A  {}\mrightarrow{}  Type.  \mforall{}X:j\mvdash{}.    \{X  \mvdash{}  \_:Equiv(\mSigma{}  discr(A)  discrete-family(A;a.B[a]);discr(a:A  \mtimes{}  B[a]))\}



Date html generated: 2020_05_20-PM-03_41_58
Last ObjectModification: 2020_04_20-PM-06_17_22

Theory : cubical!type!theory


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