Nuprl Lemma : least-equiv-induction

∀[A:Type]. ∀[P:A ⟶ ℙ]. ∀[R:A ⟶ A ⟶ ℙ].
  ((∀x,y:A.  ((x R y) ⇒ (P[x] ⇐⇒ P[y]))) ⇒ (∀x,y:A.  ((x least-equiv(A;R) y) ⇒ P[x] ⇒ P[y])))


Proof




Definitions occuring in Statement :  least-equiv: least-equiv(A;R),  uall: ∀[x:A]. B[x],  prop: ℙ,  infix_ap: x f y,  so_apply: x[s],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  implies: P ⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  all: ∀x:A. B[x],  infix_ap: x f y,  least-equiv: least-equiv(A;R),  transitive-reflexive-closure: R^*,  or: P ∨ Q,  prop: ℙ,  and: P ∧ Q,  member: t ∈ T,  so_apply: x[s],  so_lambda: λ2x.t[x],  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  and_wf,  equal_wf,  transitive-closure-induction,  or_wf,  infix_ap_wf,  least-equiv_wf,  all_wf,  iff_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  sqequalHypSubstitution,  sqequalRule,  unionElimination,  thin,  cut,  hypothesis,  addLevel,  hyp_replacement,  equalitySymmetry,  dependent_set_memberEquality,  independent_pairFormation,  hypothesisEquality,  introduction,  extract_by_obid,  isectElimination,  applyLambdaEquality,  setElimination,  rename,  productElimination,  applyEquality,  levelHypothesis,  lambdaEquality,  independent_functionElimination,  instantiate,  cumulativity,  universeEquality,  because_Cache,  dependent_functionElimination,  functionEquality

Latex:
\mforall{}[A:Type].  \mforall{}[P:A  {}\mrightarrow{}  \mBbbP{}].  \mforall{}[R:A  {}\mrightarrow{}  A  {}\mrightarrow{}  \mBbbP{}].
    ((\mforall{}x,y:A.    ((x  R  y)  {}\mRightarrow{}  (P[x]  \mLeftarrow{}{}\mRightarrow{}  P[y])))  {}\mRightarrow{}  (\mforall{}x,y:A.    ((x  least-equiv(A;R)  y)  {}\mRightarrow{}  P[x]  {}\mRightarrow{}  P[y])))



Date html generated: 2018_05_21-PM-00_52_06
Last ObjectModification: 2018_05_04-AM-10_21_29

Theory : relations2


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