Nuprl Lemma : stream-coinduction

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


Proof




Definitions occuring in Statement :  s-tl: s-tl(s) s-hd: s-hd(s) stream: stream(A) uimplies: supposing a uall: [x:A]. B[x] prop: infix_ap: y all: x:A. B[x] implies:  Q and: P ∧ Q function: x:A ⟶ B[x] universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a so_lambda: λ2x.t[x] so_apply: x[s] stream: stream(A) so_apply: x[s1;s2] infix_ap: y prop: implies:  Q and: P ∧ Q subtype_rel: A ⊆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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