Nuprl Lemma : bag-remove-size-member-no-repeats
∀[T:Type]
  ∀eq:EqDecider(T). ∀bs:bag(T). ∀x:T.  (#(bs - x) = (#(bs) - 1) ∈ ℤ) supposing (x ↓∈ bs and bag-no-repeats(T;bs))
Proof
Definitions occuring in Statement : 
bag-remove: bs - x
, 
bag-member: x ↓∈ bs
, 
bag-no-repeats: bag-no-repeats(T;bs)
, 
bag-size: #(bs)
, 
bag: bag(T)
, 
deq: EqDecider(T)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
subtract: n - m
, 
natural_number: $n
, 
int: ℤ
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
or: P ∨ Q
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
squash: ↓T
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
nat: ℕ
, 
true: True
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
false: False
Lemmas referenced : 
bag-remove-size, 
equal_wf, 
squash_wf, 
true_wf, 
subtract_wf, 
bag-size_wf, 
nat_wf, 
bag-count-member-no-repeats, 
iff_weakening_equal, 
bag-member_wf, 
bag-no-repeats_wf, 
bag_wf, 
deq_wf
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
lambdaFormation, 
dependent_functionElimination, 
unionElimination, 
productElimination, 
applyEquality, 
lambdaEquality, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
universeEquality, 
intEquality, 
cumulativity, 
setElimination, 
rename, 
sqequalRule, 
independent_isectElimination, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
because_Cache, 
independent_functionElimination, 
isect_memberEquality, 
axiomEquality, 
voidElimination
Latex:
\mforall{}[T:Type]
    \mforall{}eq:EqDecider(T).  \mforall{}bs:bag(T).  \mforall{}x:T.
        (\#(bs  -  x)  =  (\#(bs)  -  1))  supposing  (x  \mdownarrow{}\mmember{}  bs  and  bag-no-repeats(T;bs))
Date html generated:
2018_05_21-PM-09_47_54
Last ObjectModification:
2017_07_26-PM-06_30_29
Theory : bags_2
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