Nuprl Lemma : before-adjacent
∀[T:Type]
  ∀L:T List. ∀x,y:T.
    adjacent(T;L;x;y) 
⇒ (∀z:T. (z before y ∈ L 
⇒ (z before x ∈ L ∨ (z = x ∈ T)))) supposing no_repeats(T;L)
Proof
Definitions occuring in Statement : 
adjacent: adjacent(T;L;x;y)
, 
l_before: x before y ∈ l
, 
no_repeats: no_repeats(T;l)
, 
list: T List
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
or: P ∨ Q
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
so_lambda: λ2x.t[x]
, 
uimplies: b supposing a
, 
prop: ℙ
, 
implies: P 
⇒ Q
, 
or: P ∨ Q
, 
so_apply: x[s]
, 
false: False
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
guard: {T}
, 
uiff: uiff(P;Q)
, 
squash: ↓T
, 
true: True
, 
subtype_rel: A ⊆r B
, 
not: ¬A
, 
cand: A c∧ B
Lemmas referenced : 
list_induction, 
all_wf, 
isect_wf, 
no_repeats_wf, 
adjacent_wf, 
l_before_wf, 
or_wf, 
equal_wf, 
list_wf, 
no_repeats_witness, 
nil_wf, 
cons_wf, 
adjacent-nil, 
adjacent-cons, 
cons_before, 
l_member_wf, 
no_repeats_cons, 
hd-before, 
l_before_member2, 
no_repeats_iff, 
not_wf, 
squash_wf, 
true_wf, 
iff_weakening_equal, 
l_before_antisymmetry, 
adjacent-member
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
thin, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
sqequalRule, 
lambdaEquality, 
cumulativity, 
because_Cache, 
hypothesis, 
functionEquality, 
independent_functionElimination, 
rename, 
dependent_functionElimination, 
universeEquality, 
independent_isectElimination, 
voidElimination, 
productElimination, 
unionElimination, 
addLevel, 
orFunctionality, 
productEquality, 
inrFormation, 
equalityTransitivity, 
equalitySymmetry, 
applyEquality, 
imageElimination, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
hyp_replacement, 
applyLambdaEquality, 
inlFormation, 
independent_pairFormation
Latex:
\mforall{}[T:Type]
    \mforall{}L:T  List.  \mforall{}x,y:T.
        adjacent(T;L;x;y)  {}\mRightarrow{}  (\mforall{}z:T.  (z  before  y  \mmember{}  L  {}\mRightarrow{}  (z  before  x  \mmember{}  L  \mvee{}  (z  =  x)))) 
        supposing  no\_repeats(T;L)
Date html generated:
2018_05_21-PM-06_39_31
Last ObjectModification:
2017_07_26-PM-04_53_27
Theory : general
Home
Index