Nuprl Lemma : set-equal-l_contains
∀[T:Type]. ∀x,y:T List.  (set-equal(T;x;y) 
⇐⇒ x ⊆ y ∧ y ⊆ x)
Proof
Definitions occuring in Statement : 
set-equal: set-equal(T;x;y)
, 
l_contains: A ⊆ B
, 
list: T List
, 
uall: ∀[x:A]. B[x]
, 
all: ∀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]
, 
l_contains: A ⊆ B
, 
set-equal: set-equal(T;x;y)
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
rev_implies: P 
⇐ Q
, 
guard: {T}
Lemmas referenced : 
l_member_wf, 
all_wf, 
iff_wf, 
l_all_iff, 
l_all_wf, 
list_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
independent_pairFormation, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
because_Cache, 
sqequalRule, 
lambdaEquality, 
productElimination, 
productEquality, 
functionEquality, 
addLevel, 
independent_functionElimination, 
dependent_functionElimination, 
setElimination, 
rename, 
setEquality, 
universeEquality
Latex:
\mforall{}[T:Type].  \mforall{}x,y:T  List.    (set-equal(T;x;y)  \mLeftarrow{}{}\mRightarrow{}  x  \msubseteq{}  y  \mwedge{}  y  \msubseteq{}  x)
Date html generated:
2019_06_20-PM-01_30_21
Last ObjectModification:
2018_08_24-PM-11_35_14
Theory : list_1
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