Nuprl Lemma : Wzero-leq
∀[A:Type]. ∀[B:A ⟶ Type].  ∀w:W(A;a.B[a]). (isZero(w) ⇐⇒ ∀w2:W(A;a.B[a]). (w ≤  w2))
Proof
Definitions occuring in Statement : 
Wzero: isZero(w), 
Wcmp: Wcmp(A;a.B[a];leq), 
W: W(A;a.B[a]), 
btrue: tt, 
uall: ∀[x:A]. B[x], 
infix_ap: x f y, 
so_apply: x[s], 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
function: x:A ⟶ B[x], 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
infix_ap: x f y, 
implies: P ⇒ Q, 
all: ∀x:A. B[x], 
Wsup: Wsup(a;b), 
Wcmp: Wcmp(A;a.B[a];leq), 
ifthenelse: if b then t else f fi , 
btrue: tt, 
Wzero: isZero(w), 
pi1: fst(t), 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
not: ¬A, 
false: False, 
prop: ℙ, 
subtype_rel: A ⊆r B, 
rev_implies: P ⇐ Q
Lemmas referenced : 
W-induction, 
iff_wf, 
Wzero_wf, 
all_wf, 
W_wf, 
Wcmp_wf, 
btrue_wf, 
not_wf, 
bfalse_wf, 
infix_ap_wf, 
Wless_antireflexive
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
sqequalRule, 
lambdaEquality, 
applyEquality, 
hypothesis, 
independent_functionElimination, 
lambdaFormation, 
independent_pairFormation, 
voidElimination, 
because_Cache, 
cumulativity, 
instantiate, 
universeEquality, 
functionEquality, 
rename, 
dependent_functionElimination
Latex:
\mforall{}[A:Type].  \mforall{}[B:A  {}\mrightarrow{}  Type].    \mforall{}w:W(A;a.B[a]).  (isZero(w)  \mLeftarrow{}{}\mRightarrow{}  \mforall{}w2:W(A;a.B[a]).  (w  \mleq{}    w2))
Date html generated:
2016_05_14-AM-06_16_39
Last ObjectModification:
2015_12_26-PM-00_04_22
Theory : co-recursion
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