Nuprl Lemma : bag-member-bag-diff
∀[T:Type]. ∀eq:EqDecider(T). ∀x:T. ∀bs:bag(T).  uiff(x ↓∈ bs;↑isl(bag-diff(eq;bs;{x})))
Proof
Definitions occuring in Statement : 
bag-diff: bag-diff(eq;bs;as), 
bag-member: x ↓∈ bs, 
single-bag: {x}, 
bag: bag(T), 
deq: EqDecider(T), 
assert: ↑b, 
isl: isl(x), 
uiff: uiff(P;Q), 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
isl: isl(x), 
assert: ↑b, 
ifthenelse: if b then t else f fi , 
btrue: tt, 
uiff: uiff(P;Q), 
and: P ∧ Q, 
uimplies: b supposing a, 
true: True, 
prop: ℙ, 
exists: ∃x:A. B[x], 
squash: ↓T, 
bfalse: ff, 
false: False, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q, 
bag-member: x ↓∈ bs, 
not: ¬A
Lemmas referenced : 
bag-diff-property, 
single-bag_wf, 
bag-diff_wf, 
bag_wf, 
unit_wf2, 
equal_wf, 
bag-append_wf, 
true_wf, 
false_wf, 
all_wf, 
not_wf, 
iff_weakening_uiff, 
bag-member_wf, 
squash_wf, 
exists_wf, 
bag-member-iff, 
assert_witness, 
isl_wf, 
assert_wf, 
uiff_wf, 
deq_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
lambdaFormation, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
because_Cache, 
dependent_functionElimination, 
hypothesisEquality, 
cumulativity, 
hypothesis, 
unionEquality, 
unionElimination, 
sqequalRule, 
independent_pairFormation, 
natural_numberEquality, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
dependent_pairFormation, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
voidElimination, 
lambdaEquality, 
independent_functionElimination, 
addLevel, 
productElimination, 
independent_isectElimination, 
independent_pairEquality, 
isect_memberEquality, 
universeEquality
Latex:
\mforall{}[T:Type].  \mforall{}eq:EqDecider(T).  \mforall{}x:T.  \mforall{}bs:bag(T).    uiff(x  \mdownarrow{}\mmember{}  bs;\muparrow{}isl(bag-diff(eq;bs;\{x\})))
Date html generated:
2018_05_21-PM-09_49_20
Last ObjectModification:
2017_07_26-PM-06_31_00
Theory : bags_2
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