Nuprl Lemma : imax-list-ub
∀L:ℤ List. ∀a:ℤ.  a ≤ imax-list(L) ⇐⇒ (∃b∈L. a ≤ b) supposing 0 < ||L||
Proof
Definitions occuring in Statement : 
imax-list: imax-list(L), 
l_exists: (∃x∈L. P[x]), 
length: ||as||, 
list: T List, 
less_than: a < b, 
uimplies: b supposing a, 
le: A ≤ B, 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
natural_number: $n, 
int: ℤ
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
uimplies: b supposing a, 
member: t ∈ T, 
uall: ∀[x:A]. B[x], 
so_lambda: λ2x y.t[x; y], 
so_apply: x[s1;s2], 
implies: P ⇒ Q, 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
prop: ℙ, 
rev_implies: P ⇐ Q, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
or: P ∨ Q, 
cand: A c∧ B, 
assoc: Assoc(T;op), 
infix_ap: x f y, 
squash: ↓T, 
true: True, 
subtype_rel: A ⊆r B, 
guard: {T}, 
imax-list: imax-list(L)
Lemmas referenced : 
member-less_than, 
length_wf, 
combine-list-rel-or, 
imax_wf, 
le_wf, 
imax_ub, 
all_wf, 
iff_wf, 
or_wf, 
equal_wf, 
squash_wf, 
true_wf, 
imax_assoc, 
iff_weakening_equal, 
less_than_wf, 
list_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
isect_memberFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
natural_numberEquality, 
intEquality, 
hypothesisEquality, 
hypothesis, 
independent_isectElimination, 
rename, 
because_Cache, 
dependent_functionElimination, 
sqequalRule, 
lambdaEquality, 
independent_functionElimination, 
independent_pairFormation, 
addLevel, 
allFunctionality, 
productElimination, 
impliesFunctionality, 
applyEquality, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
universeEquality, 
imageMemberEquality, 
baseClosed, 
isect_memberEquality, 
axiomEquality
Latex:
\mforall{}L:\mBbbZ{}  List.  \mforall{}a:\mBbbZ{}.    a  \mleq{}  imax-list(L)  \mLeftarrow{}{}\mRightarrow{}  (\mexists{}b\mmember{}L.  a  \mleq{}  b)  supposing  0  <  ||L||
Date html generated:
2017_04_14-AM-09_23_47
Last ObjectModification:
2017_02_27-PM-03_58_27
Theory : list_1
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