Nuprl Lemma : stream-coinduction

∀[A:Type]. ∀[R:stream(A) ⟶ stream(A) ⟶ ℙ].
  ∀[x,y:stream(A)].  x = y ∈ stream(A) supposing x R y 
  supposing ∀x,y:stream(A).  ((x R y) ⇒ ((s-hd(x) = s-hd(y) ∈ A) ∧ (s-tl(x) R s-tl(y))))


Proof




Definitions occuring in Statement :  s-tl: s-tl(s),  s-hd: s-hd(s),  stream: stream(A),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  prop: ℙ,  infix_ap: x f y,  all: ∀x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  function: x:A ⟶ B[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  so_lambda: λ2x.t[x],  so_apply: x[s],  stream: stream(A),  so_apply: x[s1;s2],  infix_ap: x f y,  prop: ℙ,  implies: P ⇒ Q,  and: P ∧ Q,  subtype_rel: A ⊆r B,  F-bisimulation: x,y.R[x; y] is an T.F[T]-bisimulation,  all: ∀x:A. B[x],  s-tl: s-tl(s),  s-hd: s-hd(s),  guard: {T},  pi1: fst(t),  pi2: snd(t)
Lemmas referenced :  coinduction-principle,  continuous-monotone-product,  continuous-monotone-constant,  continuous-monotone-id,  stream_wf,  all_wf,  equal_wf,  s-hd_wf,  s-tl_wf,  corec_wf,  subtype_rel_wf,  stream-ext,  subtype_rel_product,  subtype_rel_transitivity,  subtype_rel_weakening
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  sqequalRule,  lambdaEquality,  productEquality,  cumulativity,  hypothesisEquality,  universeEquality,  independent_isectElimination,  hypothesis,  applyEquality,  functionExtensionality,  isect_memberEquality,  axiomEquality,  because_Cache,  equalityTransitivity,  equalitySymmetry,  functionEquality,  lambdaFormation,  productElimination,  dependent_functionElimination,  independent_functionElimination,  independent_pairEquality

Latex:
\mforall{}[A:Type].  \mforall{}[R:stream(A)  {}\mrightarrow{}  stream(A)  {}\mrightarrow{}  \mBbbP{}].
    \mforall{}[x,y:stream(A)].    x  =  y  supposing  x  R  y 
    supposing  \mforall{}x,y:stream(A).    ((x  R  y)  {}\mRightarrow{}  ((s-hd(x)  =  s-hd(y))  \mwedge{}  (s-tl(x)  R  s-tl(y))))



Date html generated: 2017_04_14-AM-07_47_20
Last ObjectModification: 2017_02_27-PM-03_17_41

Theory : co-recursion


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