Nuprl Lemma : list-diff-cons-single
∀[T:Type]. ∀[eq:EqDecider(T)]. ∀[as:T List]. ∀[b,x:T].  [x / as]-[b] = [x / as-[b]] ∈ (T List) supposing ¬(x = b ∈ T)
Proof
Definitions occuring in Statement : 
list-diff: as-bs, 
cons: [a / b], 
nil: [], 
list: T List, 
deq: EqDecider(T), 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
not: ¬A, 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
uimplies: b supposing a, 
squash: ↓T, 
prop: ℙ, 
true: True, 
subtype_rel: A ⊆r B, 
guard: {T}, 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
rev_implies: P ⇐ Q, 
implies: P ⇒ Q, 
all: ∀x:A. B[x], 
top: Top, 
deq: EqDecider(T), 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
exists: ∃x:A. B[x], 
or: P ∨ Q, 
sq_type: SQType(T), 
bnot: ¬bb, 
assert: ↑b, 
false: False, 
not: ¬A
Lemmas referenced : 
equal_wf, 
squash_wf, 
true_wf, 
list-diff-cons, 
cons_wf, 
nil_wf, 
list-diff_wf, 
iff_weakening_equal, 
deq_member_cons_lemma, 
deq_member_nil_lemma, 
bor_wf, 
bfalse_wf, 
bool_wf, 
eqtt_to_assert, 
assert-deq-member, 
eqff_to_assert, 
deq-member_wf, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
l_member_wf, 
not_wf, 
list_wf, 
deq_wf, 
member_singleton
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
applyEquality, 
thin, 
lambdaEquality, 
sqequalHypSubstitution, 
imageElimination, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
because_Cache, 
cumulativity, 
natural_numberEquality, 
sqequalRule, 
imageMemberEquality, 
baseClosed, 
universeEquality, 
independent_isectElimination, 
productElimination, 
independent_functionElimination, 
dependent_functionElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
setElimination, 
rename, 
lambdaFormation, 
unionElimination, 
equalityElimination, 
dependent_pairFormation, 
promote_hyp, 
instantiate, 
axiomEquality
Latex:
\mforall{}[T:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[as:T  List].  \mforall{}[b,x:T].
    [x  /  as]-[b]  =  [x  /  as-[b]]  supposing  \mneg{}(x  =  b)
Date html generated:
2017_04_17-AM-09_12_58
Last ObjectModification:
2017_02_27-PM-05_19_52
Theory : decidable!equality
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