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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