Nuprl Lemma : one_one_corr_equipollent

∀[A,B:Type].  (1-1-Corresp(A;B) ⇐⇒ A ~ B)


Proof




Definitions occuring in Statement :  equipollent: A ~ B,  one_one_corr: 1-1-Corresp(A;B),  uall: ∀[x:A]. B[x],  iff: P ⇐⇒ Q,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  one_one_corr: 1-1-Corresp(A;B),  exists: ∃x:A. B[x],  member: t ∈ T,  prop: ℙ,  rev_implies: P ⇐ Q,  sq_exists: ∃x:A [B[x]],  so_lambda: λ2x.t[x],  so_apply: x[s],  pi1: fst(t),  pi2: snd(t),  sq_stable: SqStable(P),  squash: ↓T
Lemmas referenced :  one_one_corr_wf,  sq_exists_wf,  inv_funs_wf,  pi1_wf,  pi2_wf,  equipollent-iff-inverse-funs,  equipollent_wf,  iff_wf,  exists_wf,  sq_stable__inv_funs
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  cut,  independent_pairFormation,  lambdaFormation,  sqequalHypSubstitution,  productElimination,  thin,  introduction,  extract_by_obid,  isectElimination,  hypothesisEquality,  hypothesis,  setElimination,  rename,  productEquality,  functionEquality,  sqequalRule,  lambdaEquality,  addLevel,  independent_functionElimination,  because_Cache,  universeEquality,  dependent_set_memberFormation,  independent_pairEquality,  dependent_pairFormation,  imageMemberEquality,  baseClosed,  imageElimination

Latex:
\mforall{}[A,B:Type].    (1-1-Corresp(A;B)  \mLeftarrow{}{}\mRightarrow{}  A  \msim{}  B)



Date html generated: 2019_06_20-PM-02_16_46
Last ObjectModification: 2018_08_24-PM-11_37_01

Theory : equipollence!!cardinality!


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