Nuprl Lemma : has-value-implies-dec-isatom
∀t,a,b:Base. ((t)↓ ⇒ ((t ∈ Atom) ∨ (if t is an atom then a otherwise b ~ b)))
Proof
Definitions occuring in Statement :
has-value: (a)↓,
isatom: if z is an atom then a otherwise b,
all: ∀x:A. B[x],
implies: P ⇒ Q,
or: P ∨ Q,
member: t ∈ T,
base: Base,
atom: Atom,
sqequal: s ~ t
Definitions unfolded in proof :
all: ∀x:A. B[x],
implies: P ⇒ Q,
has-value: (a)↓,
member: t ∈ T,
uall: ∀[x:A]. B[x],
or: P ∨ Q,
top: Top,
guard: {T},
prop: ℙ
Lemmas referenced :
base_wf,
equal-wf-base,
top_wf,
is-exception_wf,
has-value_wf_base
Rules used in proof :
sqequalSubstitution,
sqequalTransitivity,
computationStep,
sqequalReflexivity,
lambdaFormation,
isatomCases,
divergentSqle,
hypothesis,
cut,
lemma_by_obid,
sqequalHypSubstitution,
isectElimination,
thin,
baseClosed,
hypothesisEquality,
sqequalRule,
isatomReduceTrue,
equalityTransitivity,
equalitySymmetry,
inlFormation,
because_Cache,
sqequalIntensionalEquality,
isect_memberFormation,
introduction,
sqequalAxiom,
isect_memberEquality,
voidElimination,
voidEquality,
inrFormation,
atomEquality
Latex:
\mforall{}t,a,b:Base. ((t)\mdownarrow{} {}\mRightarrow{} ((t \mmember{} Atom) \mvee{} (if t is an atom then a otherwise b \msim{} b)))
Date html generated:
2016_05_13-PM-03_22_53
Last ObjectModification:
2016_01_14-PM-06_46_32
Theory : call!by!value_1
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