Nuprl Lemma : compat-iff-common-iseg
∀[T:Type]. ∀l1,l2:T List.  (l1 || l2 
⇐⇒ ∃l:T List. (l1 ≤ l ∧ l2 ≤ l))
Proof
Definitions occuring in Statement : 
compat: l1 || l2
, 
iseg: l1 ≤ l2
, 
list: T List
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
prop: ℙ
, 
rev_implies: P 
⇐ Q
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
compat: l1 || l2
, 
or: P ∨ Q
, 
exists: ∃x:A. B[x]
, 
cand: A c∧ B
Lemmas referenced : 
compat_wf, 
exists_wf, 
list_wf, 
and_wf, 
iseg_wf, 
iseg_weakening, 
common_iseg_compat
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
independent_pairFormation, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
sqequalRule, 
lambdaEquality, 
universeEquality, 
unionElimination, 
dependent_pairFormation, 
dependent_functionElimination, 
productElimination, 
independent_functionElimination
Latex:
\mforall{}[T:Type].  \mforall{}l1,l2:T  List.    (l1  ||  l2  \mLeftarrow{}{}\mRightarrow{}  \mexists{}l:T  List.  (l1  \mleq{}  l  \mwedge{}  l2  \mleq{}  l))
Date html generated:
2016_05_15-PM-03_46_12
Last ObjectModification:
2015_12_27-PM-01_20_46
Theory : general
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