Nuprl Lemma : list-to-set-property
∀[T:Type]
  ∀eq:EqDecider(T). ∀L:T List.  (no_repeats(T;list-to-set(eq;L)) ∧ (∀a:T. ((a ∈ list-to-set(eq;L)) ⇐⇒ (a ∈ L))))
Proof
Definitions occuring in Statement : 
list-to-set: list-to-set(eq;L), 
no_repeats: no_repeats(T;l), 
l_member: (x ∈ l), 
list: T List, 
deq: EqDecider(T), 
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], 
list-to-set: list-to-set(eq;L), 
and: P ∧ Q, 
member: t ∈ T, 
uimplies: b supposing a, 
top: Top, 
iff: P ⇐⇒ Q, 
implies: P ⇒ Q, 
prop: ℙ, 
rev_implies: P ⇐ Q, 
or: P ∨ Q, 
not: ¬A, 
false: False, 
guard: {T}
Lemmas referenced : 
no_repeats_union, 
nil_wf, 
no_repeats_nil, 
member-union, 
l_member_wf, 
l-union_wf, 
iff_wf, 
or_wf, 
list_wf, 
deq_wf, 
null_nil_lemma, 
btrue_wf, 
member-implies-null-eq-bfalse, 
btrue_neq_bfalse
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
independent_pairFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
independent_isectElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
addLevel, 
productElimination, 
impliesFunctionality, 
because_Cache, 
dependent_functionElimination, 
independent_functionElimination, 
universeEquality, 
unionElimination, 
sqequalRule, 
equalityTransitivity, 
equalitySymmetry, 
inrFormation
Latex:
\mforall{}[T:Type]
    \mforall{}eq:EqDecider(T).  \mforall{}L:T  List.
        (no\_repeats(T;list-to-set(eq;L))  \mwedge{}  (\mforall{}a:T.  ((a  \mmember{}  list-to-set(eq;L))  \mLeftarrow{}{}\mRightarrow{}  (a  \mmember{}  L))))
Date html generated:
2018_05_21-PM-00_51_14
Last ObjectModification:
2018_05_19-AM-06_40_51
Theory : decidable!equality
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