Nuprl Lemma : null_member
∀[T:Type]. ∀[L:T List]. ∀[x:T].  ¬(x ∈ L) supposing ↑null(L)
Proof
Definitions occuring in Statement : 
l_member: (x ∈ l)
, 
null: null(as)
, 
list: T List
, 
assert: ↑b
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
not: ¬A
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
false: False
, 
prop: ℙ
Lemmas referenced : 
assert_elim, 
null_wf, 
member-implies-null-eq-bfalse, 
btrue_neq_bfalse, 
l_member_wf, 
assert_wf, 
list_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
lambdaFormation, 
thin, 
hypothesis, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
independent_isectElimination, 
equalityTransitivity, 
equalitySymmetry, 
independent_functionElimination, 
voidElimination, 
sqequalRule, 
lambdaEquality, 
dependent_functionElimination, 
because_Cache, 
isect_memberEquality, 
universeEquality
Latex:
\mforall{}[T:Type].  \mforall{}[L:T  List].  \mforall{}[x:T].    \mneg{}(x  \mmember{}  L)  supposing  \muparrow{}null(L)
Date html generated:
2016_05_14-AM-07_39_34
Last ObjectModification:
2015_12_26-PM-02_13_21
Theory : list_1
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