Nuprl Lemma : strict-fun-connected_transitivity2

∀[T:Type]. ∀f:T ⟶ T. (retraction(T;f) ⇒ (∀x,y,z:T.  (y is f*(x) ⇒ z = f+(y) ⇒ z = f+(x))))


Proof




Definitions occuring in Statement :  retraction: retraction(T;f),  strict-fun-connected: y = f+(x),  fun-connected: y is f*(x),  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  implies: P ⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  strict-fun-connected: y = f+(x),  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  cand: A c∧ B,  member: t ∈ T,  guard: {T},  prop: ℙ,  not: ¬A,  false: False,  uimplies: b supposing a
Lemmas referenced :  fun-connected_transitivity,  not_wf,  equal_wf,  fun-connected_wf,  retraction_wf,  fun-connected_antisymmetry
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  isect_memberFormation,  lambdaFormation,  sqequalHypSubstitution,  productElimination,  thin,  cut,  independent_pairFormation,  hypothesis,  introduction,  extract_by_obid,  isectElimination,  hypothesisEquality,  dependent_functionElimination,  independent_functionElimination,  productEquality,  cumulativity,  functionExtensionality,  applyEquality,  functionEquality,  universeEquality,  equalitySymmetry,  hyp_replacement,  Error :applyLambdaEquality,  voidElimination,  independent_isectElimination,  equalityTransitivity

Latex:
\mforall{}[T:Type].  \mforall{}f:T  {}\mrightarrow{}  T.  (retraction(T;f)  {}\mRightarrow{}  (\mforall{}x,y,z:T.    (y  is  f*(x)  {}\mRightarrow{}  z  =  f+(y)  {}\mRightarrow{}  z  =  f+(x))))



Date html generated: 2016_10_25-AM-11_04_15
Last ObjectModification: 2016_07_12-AM-07_12_20

Theory : general


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