Nuprl Lemma : fun_with_inv_is_bij2

∀[A,B:Type].  ∀f:A ⟶ B. ((∃g:B ⟶ A. InvFuns(A;B;f;g)) ⇒ Bij(A;B;f))


Proof




Definitions occuring in Statement :  biject: Bij(A;B;f),  inv_funs: InvFuns(A;B;f;g),  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  implies: P ⇒ Q,  exists: ∃x:A. B[x],  member: t ∈ T,  uimplies: b supposing a,  prop: ℙ,  so_lambda: λ2x.t[x],  so_apply: x[s]
Lemmas referenced :  fun_with_inv_is_bij,  exists_wf,  inv_funs_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  sqequalHypSubstitution,  productElimination,  thin,  cut,  lemma_by_obid,  isectElimination,  hypothesisEquality,  dependent_functionElimination,  independent_isectElimination,  hypothesis,  functionEquality,  sqequalRule,  lambdaEquality,  universeEquality

Latex:
\mforall{}[A,B:Type].    \mforall{}f:A  {}\mrightarrow{}  B.  ((\mexists{}g:B  {}\mrightarrow{}  A.  InvFuns(A;B;f;g))  {}\mRightarrow{}  Bij(A;B;f))



Date html generated: 2016_05_15-PM-03_21_54
Last ObjectModification: 2015_12_27-PM-01_04_33

Theory : general


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