Nuprl Lemma : biject_functionality

∀[A1,B1,A2,B2:Type].  ∀f:A1 ⟶ B1. (Bij(A1;B1;f) ⇐⇒ Bij(A2;B2;f)) supposing (B1 ≡ B2 and A1 ≡ A2)


Proof




Definitions occuring in Statement :  biject: Bij(A;B;f),  ext-eq: A ≡ B,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  ext-eq: A ≡ B,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  uimplies: b supposing a,  member: t ∈ T,  and: P ∧ Q,  subtype_rel: A ⊆r B,  iff: P ⇐⇒ Q,  implies: P ⇒ Q,  biject: Bij(A;B;f),  inject: Inj(A;B;f),  guard: {T},  prop: ℙ,  surject: Surj(A;B;f),  exists: ∃x:A. B[x],  rev_implies: P ⇐ Q
Lemmas referenced :  equal_wf,  biject_wf,  subtype_rel_wf
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  isect_memberFormation,  lambdaFormation,  cut,  introduction,  sqequalHypSubstitution,  productElimination,  thin,  independent_pairEquality,  axiomEquality,  hypothesis,  rename,  independent_pairFormation,  promote_hyp,  dependent_functionElimination,  hypothesisEquality,  applyEquality,  independent_functionElimination,  equalityTransitivity,  equalitySymmetry,  hyp_replacement,  applyLambdaEquality,  extract_by_obid,  isectElimination,  cumulativity,  functionExtensionality,  because_Cache,  dependent_pairFormation,  productEquality,  functionEquality,  universeEquality

Latex:
\mforall{}[A1,B1,A2,B2:Type].    \mforall{}f:A1  {}\mrightarrow{}  B1.  (Bij(A1;B1;f)  \mLeftarrow{}{}\mRightarrow{}  Bij(A2;B2;f))  supposing  (B1  \mequiv{}  B2  and  A1  \mequiv{}  A2)



Date html generated: 2018_05_21-PM-06_33_11
Last ObjectModification: 2017_07_26-PM-04_52_04

Theory : general


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