Nuprl Lemma : intlex-cons
∀l1,l2:ℤ List. ∀x,y:ℤ.
  uiff(↑[x / l1] ≤_lex [y / l2];||l1|| < ||l2|| ∨ (x < y ∧ (||l1|| = ||l2|| ∈ ℤ)) ∨ ((x = y ∈ ℤ) ∧ (↑l1 ≤_lex l2)))
Proof
Definitions occuring in Statement : 
intlex: l1 ≤_lex l2, 
length: ||as||, 
cons: [a / b], 
list: T List, 
assert: ↑b, 
less_than: a < b, 
uiff: uiff(P;Q), 
all: ∀x:A. B[x], 
or: P ∨ Q, 
and: P ∧ Q, 
int: ℤ, 
equal: s = t ∈ T
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
intlex: l1 ≤_lex l2, 
member: t ∈ T, 
top: Top, 
has-value: (a)↓, 
uall: ∀[x:A]. B[x], 
uimplies: b supposing a, 
nat: ℕ, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
decidable: Dec(P), 
or: P ∨ Q, 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
implies: P ⇒ Q, 
true: True, 
prop: ℙ, 
rev_implies: P ⇐ Q, 
uiff: uiff(P;Q), 
assert: ↑b, 
ifthenelse: if b then t else f fi , 
btrue: tt, 
sq_type: SQType(T), 
guard: {T}, 
not: ¬A, 
false: False, 
subtract: n - m, 
subtype_rel: A ⊆r B, 
le: A ≤ B, 
less_than': less_than'(a;b), 
bfalse: ff, 
bor: p ∨bq, 
squash: ↓T, 
band: p ∧b q, 
intlex-aux: intlex-aux(l1;l2), 
cons: [a / b], 
so_lambda: λ2x y.t[x; y], 
so_apply: x[s1;s2], 
exposed-it: exposed-it, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
less_than: a < b, 
cand: A c∧ B, 
exists: ∃x:A. B[x], 
bnot: ¬bb, 
nequal: a ≠ b ∈ T , 
rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced : 
length_of_cons_lemma, 
value-type-has-value, 
int-value-type, 
length_wf, 
nat_wf, 
set-value-type, 
le_wf, 
length_wf_nat, 
decidable__lt, 
list_wf, 
subtype_base_sq, 
bool_wf, 
bool_subtype_base, 
iff_imp_equal_bool, 
lt_int_wf, 
btrue_wf, 
less_than_wf, 
true_wf, 
assert_of_lt_int, 
assert_wf, 
iff_wf, 
false_wf, 
not-lt-2, 
less-iff-le, 
condition-implies-le, 
add-associates, 
minus-add, 
minus-one-mul, 
add-swap, 
minus-one-mul-top, 
zero-add, 
add-commutes, 
add_functionality_wrt_le, 
le-add-cancel2, 
testxxx_lemma, 
or_wf, 
and_wf, 
equal_wf, 
le-add-cancel, 
equal-wf-base, 
list_subtype_base, 
int_subtype_base, 
bfalse_wf, 
decidable__equal_int, 
squash_wf, 
eq_int_eq_true, 
iff_weakening_equal, 
spread_cons_lemma, 
eqtt_to_assert, 
top_wf, 
assert_witness, 
unit_wf2, 
intlex-aux_wf, 
eqff_to_assert, 
bool_cases_sqequal, 
assert-bnot, 
eq_int_wf, 
assert_of_eq_int, 
neg_assert_of_eq_int, 
eq_int_eq_false, 
not-equal-2, 
decidable__le, 
not-le-2
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
sqequalRule, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
hypothesis, 
callbyvalueReduce, 
isectElimination, 
intEquality, 
independent_isectElimination, 
addEquality, 
hypothesisEquality, 
natural_numberEquality, 
because_Cache, 
lambdaEquality, 
unionElimination, 
instantiate, 
cumulativity, 
independent_pairFormation, 
addLevel, 
productElimination, 
impliesFunctionality, 
equalityTransitivity, 
equalitySymmetry, 
independent_functionElimination, 
applyEquality, 
minusEquality, 
isect_memberFormation, 
axiomEquality, 
rename, 
inlFormation, 
orFunctionality, 
productEquality, 
baseApply, 
closedConclusion, 
baseClosed, 
imageElimination, 
universeEquality, 
imageMemberEquality, 
equalityElimination, 
lessCases, 
sqequalAxiom, 
inlEquality, 
inrFormation, 
dependent_set_memberEquality, 
dependent_pairFormation, 
promote_hyp, 
int_eqReduceTrueSq, 
int_eqReduceFalseSq
Latex:
\mforall{}l1,l2:\mBbbZ{}  List.  \mforall{}x,y:\mBbbZ{}.
    uiff(\muparrow{}[x  /  l1]  \mleq{}\_lex  [y  /  l2];||l1||  <  ||l2||
    \mvee{}  (x  <  y  \mwedge{}  (||l1||  =  ||l2||))
    \mvee{}  ((x  =  y)  \mwedge{}  (\muparrow{}l1  \mleq{}\_lex  l2)))
Date html generated:
2017_09_29-PM-05_49_43
Last ObjectModification:
2017_07_26-PM-01_37_54
Theory : list_0
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