Nuprl Lemma : absval_ubound
∀[i:ℤ]. ∀[n:ℕ].  uiff(|i| ≤ n;((-n) ≤ i) ∧ (i ≤ n))
Proof
Definitions occuring in Statement : 
absval: |i|, 
nat: ℕ, 
uiff: uiff(P;Q), 
uall: ∀[x:A]. B[x], 
le: A ≤ B, 
and: P ∧ Q, 
minus: -n, 
int: ℤ
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
nat: ℕ, 
ge: i ≥ j , 
uimplies: b supposing a, 
all: ∀x:A. B[x], 
uiff: uiff(P;Q), 
and: P ∧ Q, 
le: A ≤ B, 
implies: P ⇒ Q, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
less_than: a < b, 
less_than': less_than'(a;b), 
true: True, 
squash: ↓T, 
not: ¬A, 
false: False, 
cand: A c∧ B, 
decidable: Dec(P), 
or: P ∨ Q, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q, 
subtract: n - m, 
bfalse: ff, 
exists: ∃x:A. B[x], 
sq_type: SQType(T), 
guard: {T}, 
bnot: ¬bb, 
ifthenelse: if b then t else f fi , 
assert: ↑b, 
prop: ℙ, 
rev_uimplies: rev_uimplies(P;Q), 
subtype_rel: A ⊆r B, 
top: Top
Lemmas referenced : 
absval_unfold, 
nat_properties, 
add_functionality_wrt_le, 
le_reflexive, 
le_witness_for_triv, 
istype-nat, 
istype-int, 
minus-one-mul, 
zero-add, 
add-mul-special, 
zero-mul, 
lt_int_wf, 
eqtt_to_assert, 
assert_of_lt_int, 
istype-top, 
decidable__le, 
minus-one-mul-top, 
istype-false, 
not-le-2, 
less-iff-le, 
condition-implies-le, 
minus-add, 
add-swap, 
add-commutes, 
minus-minus, 
mul-associates, 
one-mul, 
add-associates, 
le-add-cancel, 
istype-le, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_wf, 
bool_subtype_base, 
iff_transitivity, 
assert_wf, 
bnot_wf, 
not_wf, 
less_than_wf, 
iff_weakening_uiff, 
assert_of_bnot, 
istype-less_than, 
istype-assert, 
istype-void, 
not-lt-2, 
le-add-cancel2, 
le_functionality, 
le_weakening, 
minus-le, 
le-iff-nonneg, 
add-is-int-iff, 
int_subtype_base, 
subtract_wf, 
add-zero
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
sqequalRule, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
setElimination, 
rename, 
natural_numberEquality, 
minusEquality, 
because_Cache, 
independent_isectElimination, 
dependent_functionElimination, 
productElimination, 
independent_pairEquality, 
isect_memberEquality_alt, 
equalityTransitivity, 
equalitySymmetry, 
isectIsTypeImplies, 
inhabitedIsType, 
multiplyEquality, 
Error :memTop, 
lambdaFormation_alt, 
unionElimination, 
equalityElimination, 
lessCases, 
axiomSqEquality, 
independent_pairFormation, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
voidElimination, 
independent_functionElimination, 
addEquality, 
productIsType, 
dependent_pairFormation_alt, 
equalityIstype, 
promote_hyp, 
instantiate, 
cumulativity, 
functionIsType, 
universeIsType, 
baseApply, 
closedConclusion, 
applyEquality, 
intEquality, 
voidEquality, 
isect_memberEquality, 
lambdaEquality
Latex:
\mforall{}[i:\mBbbZ{}].  \mforall{}[n:\mBbbN{}].    uiff(|i|  \mleq{}  n;((-n)  \mleq{}  i)  \mwedge{}  (i  \mleq{}  n))
Date html generated:
2020_05_19-PM-09_35_23
Last ObjectModification:
2020_01_04-PM-07_56_38
Theory : arithmetic
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