Nuprl Lemma : rel_plus_iff

∀[T:Type]. ∀[R:T ⟶ T ⟶ ℙ].  ∀x,z:T.  (x R+ z ⇐⇒ ∃y:T. ((x (R^*) y) ∧ (y R z)))


Proof




Definitions occuring in Statement :  rel_plus: R+,  rel_star: R^*,  uall: ∀[x:A]. B[x],  prop: ℙ,  infix_ap: x f y,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  member: t ∈ T,  infix_ap: x f y,  prop: ℙ,  rev_implies: P ⇐ Q,  exists: ∃x:A. B[x],  so_lambda: λ2x.t[x],  so_apply: x[s],  or: P ∨ Q,  cand: A c∧ B,  uimplies: b supposing a,  subtype_rel: A ⊆r B
Lemmas referenced :  rel_plus_wf,  exists_wf,  and_wf,  rel_star_wf,  rel_plus_implies,  rel_star_weakening,  rel-plus-rel-star,  rel-star-rel-plus
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  independent_pairFormation,  applyEquality,  cut,  lemma_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  sqequalRule,  hypothesis,  productElimination,  lambdaEquality,  functionEquality,  cumulativity,  universeEquality,  dependent_functionElimination,  independent_functionElimination,  unionElimination,  dependent_pairFormation,  because_Cache,  independent_isectElimination,  productEquality

Latex:
\mforall{}[T:Type].  \mforall{}[R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].    \mforall{}x,z:T.    (x  R\msupplus{}  z  \mLeftarrow{}{}\mRightarrow{}  \mexists{}y:T.  ((x  rel\_star(T;  R)  y)  \mwedge{}  (y  R  z)))



Date html generated: 2016_05_14-PM-03_53_47
Last ObjectModification: 2015_12_26-PM-06_56_33

Theory : relations2


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