Nuprl Lemma : ispair-or-isaxiom-append-nil
∀l:Base. ((l @ [])↓ ⇒ ((↑ispair(l @ [])) ∨ (↑isaxiom(l @ []))))
Proof
Definitions occuring in Statement : 
append: as @ bs, 
nil: [], 
has-value: (a)↓, 
assert: ↑b, 
bfalse: ff, 
btrue: tt, 
ispair: if z is a pair then a otherwise b, 
isaxiom: if z = Ax then a otherwise b, 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
or: P ∨ Q, 
base: Base
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
member: t ∈ T, 
or: P ∨ Q, 
has-value: (a)↓, 
assert: ↑b, 
ifthenelse: if b then t else f fi , 
btrue: tt, 
bfalse: ff, 
true: True, 
prop: ℙ, 
top: Top, 
guard: {T}, 
uall: ∀[x:A]. B[x], 
uiff: uiff(P;Q), 
and: P ∧ Q, 
uimplies: b supposing a, 
append: as @ bs, 
list_ind: list_ind, 
cons: [a / b], 
not: ¬A, 
false: False, 
nil: [], 
it: ⋅
Lemmas referenced : 
bottom_diverge, 
assert_of_bnot, 
bfalse_wf, 
btrue_wf, 
is-exception_wf, 
sqeqff_to_assert, 
base_wf, 
has-value_wf_base, 
has-value-implies-dec-isaxiom-2, 
top_wf, 
false_wf, 
has-value-implies-dec-ispair-2
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
sqequalRule, 
baseApply, 
closedConclusion, 
baseClosed, 
hypothesisEquality, 
independent_functionElimination, 
hypothesis, 
unionElimination, 
inlFormation, 
natural_numberEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
inrFormation, 
because_Cache, 
isectElimination, 
isaxiomCases, 
divergentSqle, 
isect_memberFormation, 
introduction, 
sqequalAxiom, 
productElimination, 
independent_isectElimination, 
ispairCases, 
callbyvalueCallbyvalue, 
callbyvalueReduce
Latex:
\mforall{}l:Base.  ((l  @  [])\mdownarrow{}  {}\mRightarrow{}  ((\muparrow{}ispair(l  @  []))  \mvee{}  (\muparrow{}isaxiom(l  @  []))))
Date html generated:
2016_05_14-AM-06_31_23
Last ObjectModification:
2016_01_14-PM-08_24_56
Theory : list_0
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