Nuprl Lemma : nil_member
∀[T:Type]. ∀x:T. ((x ∈ []) ⇐⇒ False)
Proof
Definitions occuring in Statement : 
l_member: (x ∈ l), 
nil: [], 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
false: False, 
universe: Type
Definitions unfolded in proof : 
l_member: (x ∈ l), 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
implies: P ⇒ Q, 
false: False, 
select: L[n], 
member: t ∈ T, 
uimplies: b supposing a, 
nil: [], 
it: ⋅, 
so_lambda: λ2x y.t[x; y], 
top: Top, 
so_apply: x[s1;s2], 
exists: ∃x:A. B[x], 
cand: A c∧ B, 
nat: ℕ, 
guard: {T}, 
prop: ℙ, 
so_lambda: λ2x.t[x], 
sq_stable: SqStable(P), 
squash: ↓T, 
so_apply: x[s], 
rev_implies: P ⇐ Q
Lemmas referenced : 
length_of_nil_lemma, 
stuck-spread, 
base_wf, 
less_than_transitivity1, 
less_than_irreflexivity, 
exists_wf, 
nat_wf, 
less_than_wf, 
length_wf, 
nil_wf, 
equal_wf, 
select_wf, 
sq_stable__le, 
false_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberFormation, 
lambdaFormation, 
independent_pairFormation, 
cut, 
sqequalHypSubstitution, 
introduction, 
extract_by_obid, 
hypothesis, 
isectElimination, 
thin, 
baseClosed, 
independent_isectElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
productElimination, 
setElimination, 
rename, 
hypothesisEquality, 
natural_numberEquality, 
independent_functionElimination, 
lambdaEquality, 
productEquality, 
because_Cache, 
cumulativity, 
imageMemberEquality, 
imageElimination, 
universeEquality
Latex:
\mforall{}[T:Type].  \mforall{}x:T.  ((x  \mmember{}  [])  \mLeftarrow{}{}\mRightarrow{}  False)
Date html generated:
2017_04_14-AM-08_37_14
Last ObjectModification:
2017_02_27-PM-03_28_55
Theory : list_0
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