Nuprl Lemma : member-insert-by
∀[T:Type]
  ∀eq,r:T ⟶ T ⟶ 𝔹.
    ∀x:T. ∀L:T List. ∀z:T.  ((z ∈ insert-by(eq;r;x;L)) 
⇐⇒ (z = x ∈ T) ∨ (z ∈ L)) 
    supposing ∀a,b:T.  (↑(eq a b) 
⇐⇒ a = b ∈ T)
Proof
Definitions occuring in Statement : 
insert-by: insert-by(eq;r;x;l)
, 
l_member: (x ∈ l)
, 
list: T List
, 
assert: ↑b
, 
bool: 𝔹
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
or: P ∨ Q
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
prop: ℙ
, 
rev_implies: P 
⇐ Q
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
insert-by: insert-by(eq;r;x;l)
, 
so_lambda: so_lambda(x,y,z.t[x; y; z])
, 
top: Top
, 
so_apply: x[s1;s2;s3]
, 
or: P ∨ Q
, 
false: False
, 
guard: {T}
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
btrue: tt
, 
uiff: uiff(P;Q)
, 
ifthenelse: if b then t else f fi 
, 
bfalse: ff
Lemmas referenced : 
assert_wf, 
assert_witness, 
equal_wf, 
list_induction, 
all_wf, 
iff_wf, 
l_member_wf, 
insert-by_wf, 
or_wf, 
list_wf, 
list_ind_nil_lemma, 
false_wf, 
nil_member, 
nil_wf, 
member_singleton, 
cons_wf, 
list_ind_cons_lemma, 
bool_wf, 
cons_member, 
equal-wf-T-base, 
bnot_wf, 
not_wf, 
eqtt_to_assert, 
uiff_transitivity, 
eqff_to_assert, 
assert_of_bnot, 
and_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
introduction, 
sqequalRule, 
sqequalHypSubstitution, 
lambdaEquality, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
productElimination, 
independent_pairEquality, 
axiomEquality, 
hypothesis, 
extract_by_obid, 
isectElimination, 
applyEquality, 
functionExtensionality, 
cumulativity, 
independent_functionElimination, 
rename, 
because_Cache, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
independent_pairFormation, 
inlFormation, 
unionElimination, 
addLevel, 
impliesFunctionality, 
orFunctionality, 
functionEquality, 
universeEquality, 
equalityTransitivity, 
equalitySymmetry, 
inrFormation, 
baseClosed, 
equalityElimination, 
independent_isectElimination, 
hyp_replacement, 
dependent_set_memberEquality, 
applyLambdaEquality, 
setElimination
Latex:
\mforall{}[T:Type]
    \mforall{}eq,r:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbB{}.
        \mforall{}x:T.  \mforall{}L:T  List.  \mforall{}z:T.    ((z  \mmember{}  insert-by(eq;r;x;L))  \mLeftarrow{}{}\mRightarrow{}  (z  =  x)  \mvee{}  (z  \mmember{}  L)) 
        supposing  \mforall{}a,b:T.    (\muparrow{}(eq  a  b)  \mLeftarrow{}{}\mRightarrow{}  a  =  b)
Date html generated:
2017_04_17-AM-08_26_08
Last ObjectModification:
2017_02_27-PM-04_48_20
Theory : list_1
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