Nuprl Lemma : remove-first-no_repeats-member
∀[T:Type]
  ∀L:T List. ∀P:{x:T| (x ∈ L)}  ⟶ 𝔹. ∀x:T.
    (no_repeats(T;L)
    
⇒ (∀a,b:{x:T| (x ∈ L)} .  (((↑(P a)) ∧ (↑(P b))) 
⇒ (a = b ∈ T)))
    
⇒ ((x ∈ remove-first(P;L)) 
⇐⇒ (x ∈ L) ∧ (↑¬b(P x))))
Proof
Definitions occuring in Statement : 
remove-first: remove-first(P;L)
, 
no_repeats: no_repeats(T;l)
, 
l_member: (x ∈ l)
, 
list: T List
, 
bnot: ¬bb
, 
assert: ↑b
, 
bool: 𝔹
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
set: {x:A| B[x]} 
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
so_apply: x[s1;s2;s3]
, 
top: Top
, 
so_lambda: so_lambda3, 
remove-first: remove-first(P;L)
, 
rev_implies: P 
⇐ Q
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
so_apply: x[s]
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
member: t ∈ T
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
uall: ∀[x:A]. B[x]
, 
false: False
, 
not: ¬A
, 
uiff: uiff(P;Q)
, 
assert: ↑b
, 
bnot: ¬bb
, 
guard: {T}
, 
sq_type: SQType(T)
, 
or: P ∨ Q
, 
exists: ∃x:A. B[x]
, 
bfalse: ff
, 
ifthenelse: if b then t else f fi 
, 
btrue: tt
, 
it: ⋅
, 
unit: Unit
, 
bool: 𝔹
, 
rev_uimplies: rev_uimplies(P;Q)
, 
cand: A c∧ B
Lemmas referenced : 
equal_wf, 
list_ind_cons_lemma, 
list_ind_nil_lemma, 
list_wf, 
bnot_wf, 
assert_wf, 
set_wf, 
bool_wf, 
subtype_rel_dep_function, 
remove-first_wf, 
l_member_wf, 
iff_wf, 
all_wf, 
no_repeats_wf, 
list_induction, 
assert_witness, 
btrue_neq_bfalse, 
btrue_wf, 
null_nil_lemma, 
nil_wf, 
member-implies-null-eq-bfalse, 
cons_wf, 
no_repeats_cons, 
assert-bnot, 
bool_subtype_base, 
subtype_base_sq, 
bool_cases_sqequal, 
eqff_to_assert, 
eqtt_to_assert, 
assert_of_bnot, 
cons_member, 
not_wf, 
or_wf, 
and_wf, 
assert_elim, 
not_assert_elim, 
subtype_rel_self, 
remove-first-member-implies, 
bfalse_wf, 
istype-assert, 
list-subtype, 
no_repeats-subtype, 
istype-universe, 
l_member-settype
Rules used in proof : 
cut, 
universeEquality, 
voidEquality, 
voidElimination, 
isect_memberEquality, 
dependent_functionElimination, 
independent_functionElimination, 
functionExtensionality, 
productEquality, 
rename, 
setElimination, 
independent_isectElimination, 
setEquality, 
applyEquality, 
because_Cache, 
hypothesis, 
cumulativity, 
functionEquality, 
lambdaEquality, 
sqequalRule, 
hypothesisEquality, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
thin, 
lambdaFormation, 
isect_memberFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
productElimination, 
equalitySymmetry, 
equalityTransitivity, 
independent_pairFormation, 
instantiate, 
promote_hyp, 
dependent_pairFormation, 
equalityElimination, 
unionElimination, 
andLevelFunctionality, 
impliesFunctionality, 
addLevel, 
inrFormation, 
levelHypothesis, 
applyLambdaEquality, 
dependent_set_memberEquality, 
hyp_replacement, 
inlFormation, 
isect_memberFormation_alt, 
lambdaFormation_alt, 
dependent_set_memberEquality_alt, 
universeIsType, 
lambdaEquality_alt, 
setIsType, 
functionIsType, 
productIsType, 
equalityIstype, 
inhabitedIsType
Latex:
\mforall{}[T:Type]
    \mforall{}L:T  List.  \mforall{}P:\{x:T|  (x  \mmember{}  L)\}    {}\mrightarrow{}  \mBbbB{}.  \mforall{}x:T.
        (no\_repeats(T;L)
        {}\mRightarrow{}  (\mforall{}a,b:\{x:T|  (x  \mmember{}  L)\}  .    (((\muparrow{}(P  a))  \mwedge{}  (\muparrow{}(P  b)))  {}\mRightarrow{}  (a  =  b)))
        {}\mRightarrow{}  ((x  \mmember{}  remove-first(P;L))  \mLeftarrow{}{}\mRightarrow{}  (x  \mmember{}  L)  \mwedge{}  (\muparrow{}\mneg{}\msubb{}(P  x))))
Date html generated:
2020_05_19-PM-09_45_37
Last ObjectModification:
2020_01_04-PM-07_59_45
Theory : list_1
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