Nuprl Lemma : absval_zero
∀[i:ℤ]. uiff(|i| = 0 ∈ ℤ;i = 0 ∈ ℤ)
Proof
Definitions occuring in Statement : 
absval: |i|
, 
uiff: uiff(P;Q)
, 
uall: ∀[x:A]. B[x]
, 
natural_number: $n
, 
int: ℤ
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
btrue: tt
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
less_than: a < b
, 
less_than': less_than'(a;b)
, 
top: Top
, 
true: True
, 
squash: ↓T
, 
not: ¬A
, 
false: False
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
bfalse: ff
, 
exists: ∃x:A. B[x]
, 
or: P ∨ Q
, 
sq_type: SQType(T)
, 
guard: {T}
, 
bnot: ¬bb
, 
ifthenelse: if b then t else f fi 
, 
assert: ↑b
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
absval_unfold2, 
lt_int_wf, 
bool_wf, 
eqtt_to_assert, 
assert_of_lt_int, 
top_wf, 
less_than_wf, 
equal-wf-base, 
int_subtype_base, 
eqff_to_assert, 
equal_wf, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
iff_transitivity, 
assert_wf, 
bnot_wf, 
not_wf, 
iff_weakening_uiff, 
assert_of_bnot, 
minus-one-mul, 
add-commutes, 
minus-one-mul-top, 
add-mul-special, 
zero-mul, 
zero-add, 
minus-zero
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalRule, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
natural_numberEquality, 
lambdaFormation, 
unionElimination, 
equalityElimination, 
equalityTransitivity, 
equalitySymmetry, 
productElimination, 
independent_isectElimination, 
because_Cache, 
lessCases, 
sqequalAxiom, 
isect_memberEquality, 
independent_pairFormation, 
voidElimination, 
voidEquality, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
independent_functionElimination, 
intEquality, 
applyEquality, 
dependent_pairFormation, 
promote_hyp, 
dependent_functionElimination, 
instantiate, 
cumulativity, 
impliesFunctionality, 
independent_pairEquality, 
axiomEquality, 
baseApply, 
closedConclusion, 
addEquality, 
lambdaEquality, 
minusEquality
Latex:
\mforall{}[i:\mBbbZ{}].  uiff(|i|  =  0;i  =  0)
Date html generated:
2017_04_14-AM-07_17_01
Last ObjectModification:
2017_02_27-PM-02_51_43
Theory : arithmetic
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