Nuprl Lemma : adjacent-cons
∀[T:Type]
  ∀x,y,u:T. ∀L:T List.  (adjacent(T;[u / L];x;y) 
⇐⇒ 0 < ||L|| ∧ (((x = u ∈ T) ∧ (y = hd(L) ∈ T)) ∨ adjacent(T;L;x;y)))
Proof
Definitions occuring in Statement : 
adjacent: adjacent(T;L;x;y)
, 
hd: hd(l)
, 
length: ||as||
, 
cons: [a / b]
, 
list: T List
, 
less_than: a < b
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
or: P ∨ Q
, 
and: P ∧ Q
, 
natural_number: $n
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
adjacent: adjacent(T;L;x;y)
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
top: Top
, 
uall: ∀[x:A]. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
exists: ∃x:A. B[x]
, 
guard: {T}
, 
int_seg: {i..j-}
, 
lelt: i ≤ j < k
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
false: False
, 
less_than: a < b
, 
squash: ↓T
, 
uiff: uiff(P;Q)
, 
uimplies: b supposing a
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
not: ¬A
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
ge: i ≥ j 
, 
le: A ≤ B
, 
so_apply: x[s]
, 
rev_implies: P 
⇐ Q
, 
sq_type: SQType(T)
, 
select: L[n]
, 
cons: [a / b]
, 
subtract: n - m
, 
cand: A c∧ B
, 
less_than': less_than'(a;b)
Lemmas referenced : 
length_of_cons_lemma, 
int_seg_properties, 
decidable__lt, 
length_wf, 
subtract-is-int-iff, 
add-is-int-iff, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformnot_wf, 
intformless_wf, 
itermConstant_wf, 
itermVar_wf, 
itermSubtract_wf, 
itermAdd_wf, 
intformle_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_less_lemma, 
int_term_value_constant_lemma, 
int_term_value_var_lemma, 
int_term_value_subtract_lemma, 
int_term_value_add_lemma, 
int_formula_prop_le_lemma, 
int_formula_prop_wf, 
false_wf, 
exists_wf, 
int_seg_wf, 
subtract_wf, 
equal_wf, 
select_wf, 
cons_wf, 
decidable__le, 
non_neg_length, 
less_than_wf, 
or_wf, 
hd_wf, 
list_wf, 
decidable__equal_int, 
subtype_base_sq, 
int_subtype_base, 
select0, 
intformeq_wf, 
int_formula_prop_eq_lemma, 
lelt_wf, 
select-cons-tl, 
general_arith_equation1, 
add-member-int_seg2, 
add-subtract-cancel
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
hypothesis, 
isect_memberFormation, 
lambdaFormation, 
independent_pairFormation, 
productElimination, 
isectElimination, 
because_Cache, 
hypothesisEquality, 
setElimination, 
rename, 
cumulativity, 
unionElimination, 
pointwiseFunctionality, 
equalityTransitivity, 
equalitySymmetry, 
promote_hyp, 
imageElimination, 
baseApply, 
closedConclusion, 
baseClosed, 
independent_isectElimination, 
natural_numberEquality, 
dependent_pairFormation, 
lambdaEquality, 
int_eqEquality, 
intEquality, 
computeAll, 
addEquality, 
productEquality, 
universeEquality, 
instantiate, 
independent_functionElimination, 
inlFormation, 
inrFormation, 
dependent_set_memberEquality
Latex:
\mforall{}[T:Type]
    \mforall{}x,y,u:T.  \mforall{}L:T  List.
        (adjacent(T;[u  /  L];x;y)  \mLeftarrow{}{}\mRightarrow{}  0  <  ||L||  \mwedge{}  (((x  =  u)  \mwedge{}  (y  =  hd(L)))  \mvee{}  adjacent(T;L;x;y)))
Date html generated:
2018_05_21-PM-06_32_44
Last ObjectModification:
2017_07_26-PM-04_51_47
Theory : general
Home
Index