Nuprl Lemma : fseg_nil
∀[T:Type]. ∀L:T List. (fseg(T;L;[])
⇐⇒ ↑null(L))
Proof
Definitions occuring in Statement :
fseg: fseg(T;L1;L2)
,
null: null(as)
,
nil: []
,
list: T List
,
assert: ↑b
,
uall: ∀[x:A]. B[x]
,
all: ∀x:A. B[x]
,
iff: P
⇐⇒ Q
,
universe: Type
Definitions unfolded in proof :
fseg: fseg(T;L1;L2)
,
uall: ∀[x:A]. B[x]
,
all: ∀x:A. B[x]
,
member: t ∈ T
,
so_lambda: λ2x.t[x]
,
so_apply: x[s]
,
implies: P
⇒ Q
,
assert: ↑b
,
ifthenelse: if b then t else f fi
,
btrue: tt
,
top: Top
,
bfalse: ff
,
prop: ℙ
,
iff: P
⇐⇒ Q
,
and: P ∧ Q
,
rev_implies: P
⇐ Q
,
decidable: Dec(P)
,
or: P ∨ Q
,
true: True
,
not: ¬A
,
false: False
,
exists: ∃x:A. B[x]
,
append: as @ bs
,
so_lambda: so_lambda(x,y,z.t[x; y; z])
,
so_apply: x[s1;s2;s3]
,
uiff: uiff(P;Q)
,
uimplies: b supposing a
Lemmas referenced :
list_induction,
iff_wf,
exists_wf,
list_wf,
equal-wf-base-T,
assert_wf,
null_wf,
null_nil_lemma,
null_cons_lemma,
append_wf,
decidable__true,
nil_wf,
list_ind_nil_lemma,
cons_wf,
false_wf,
decidable__false,
btrue_wf,
append_is_nil,
and_wf,
equal_wf,
bfalse_wf,
btrue_neq_bfalse
Rules used in proof :
sqequalSubstitution,
sqequalRule,
sqequalReflexivity,
sqequalTransitivity,
computationStep,
isect_memberFormation,
lambdaFormation,
cut,
thin,
introduction,
extract_by_obid,
sqequalHypSubstitution,
isectElimination,
hypothesisEquality,
lambdaEquality,
hypothesis,
because_Cache,
independent_functionElimination,
rename,
dependent_functionElimination,
isect_memberEquality,
voidElimination,
voidEquality,
baseClosed,
independent_pairFormation,
unionElimination,
natural_numberEquality,
dependent_pairFormation,
productElimination,
equalitySymmetry,
independent_isectElimination,
dependent_set_memberEquality,
equalityTransitivity,
applyLambdaEquality,
setElimination,
addLevel,
levelHypothesis
Latex:
\mforall{}[T:Type]. \mforall{}L:T List. (fseg(T;L;[]) \mLeftarrow{}{}\mRightarrow{} \muparrow{}null(L))
Date html generated:
2018_05_21-PM-06_30_24
Last ObjectModification:
2018_05_19-PM-04_40_56
Theory : general
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