Nuprl Lemma : hd-stream-zip
∀[f:Top]. ∀[as,bs:stream(Top)].  (s-hd(stream-zip(f;as;bs)) ~ f s-hd(as) s-hd(bs))
Proof
Definitions occuring in Statement : 
stream-zip: stream-zip(f;as;bs), 
s-hd: s-hd(s), 
stream: stream(A), 
uall: ∀[x:A]. B[x], 
top: Top, 
apply: f a, 
sqequal: s ~ t
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
nat: ℕ, 
le: A ≤ B, 
and: P ∧ Q, 
less_than': less_than'(a;b), 
false: False, 
not: ¬A, 
implies: P ⇒ Q, 
prop: ℙ, 
s-nth: s-nth(n;s), 
eq_int: (i =z j), 
subtract: n - m, 
ifthenelse: if b then t else f fi , 
btrue: tt, 
pi1: fst(t), 
s-hd: s-hd(s)
Lemmas referenced : 
nth-stream-zip, 
false_wf, 
le_wf, 
stream_wf, 
top_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
dependent_set_memberEquality, 
natural_numberEquality, 
sqequalRule, 
independent_pairFormation, 
lambdaFormation, 
hypothesis, 
callbyvalueReduce, 
sqleReflexivity, 
sqequalAxiom, 
isect_memberEquality, 
because_Cache
Latex:
\mforall{}[f:Top].  \mforall{}[as,bs:stream(Top)].    (s-hd(stream-zip(f;as;bs))  \msim{}  f  s-hd(as)  s-hd(bs))
Date html generated:
2016_05_14-AM-06_23_35
Last ObjectModification:
2015_12_26-AM-11_58_46
Theory : co-recursion
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