Nuprl Lemma : equiv-discrete-type

∀A,B:Type. ∀f:A ⟶ B.  (Bij(A;B;f) ⇒ (∀X:j⊢. {X ⊢ _:Equiv(discr(A);discr(B))}))


Proof




Definitions occuring in Statement :  cubical-equiv: Equiv(T;A),  discrete-cubical-type: discr(T),  cubical-term: {X ⊢ _:A},  cubical_set: CubicalSet,  biject: Bij(A;B;f),  all: ∀x:A. B[x],  implies: P ⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  uall: ∀[x:A]. B[x],  member: t ∈ T,  exists: ∃x:A. B[x],  and: P ∧ Q,  uimplies: b supposing a,  subtype_rel: A ⊆r B,  prop: ℙ
Lemmas referenced :  biject-inverse,  bijection-equiv_wf,  cubical_set_cumulativity-i-j,  cubical_set_wf,  biject_wf,  istype-universe
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  independent_functionElimination,  hypothesis,  productElimination,  instantiate,  cumulativity,  independent_isectElimination,  applyEquality,  sqequalRule,  universeIsType,  functionIsType,  inhabitedIsType,  universeEquality

Latex:
\mforall{}A,B:Type.  \mforall{}f:A  {}\mrightarrow{}  B.    (Bij(A;B;f)  {}\mRightarrow{}  (\mforall{}X:j\mvdash{}.  \{X  \mvdash{}  \_:Equiv(discr(A);discr(B))\}))



Date html generated: 2020_05_20-PM-03_43_05
Last ObjectModification: 2020_04_06-PM-07_14_26

Theory : cubical!type!theory


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