Nuprl Lemma : square_non_neg
∀x:ℤ. (0 ≤ (x * x))
Proof
Definitions occuring in Statement : 
le: A ≤ B, 
all: ∀x:A. B[x], 
multiply: n * m, 
natural_number: $n, 
int: ℤ
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
subtype_rel: A ⊆r B, 
nat: ℕ, 
uimplies: b supposing a, 
prop: ℙ, 
squash: ↓T, 
decidable: Dec(P), 
or: P ∨ Q, 
false: False, 
le: A ≤ B, 
and: P ∧ Q, 
uiff: uiff(P;Q), 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
exists: ∃x:A. B[x], 
implies: P ⇒ Q, 
not: ¬A, 
top: Top, 
true: True, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
less_than: a < b, 
less_than': less_than'(a;b), 
bfalse: ff, 
sq_type: SQType(T), 
guard: {T}, 
bnot: ¬bb, 
ifthenelse: if b then t else f fi , 
assert: ↑b
Lemmas referenced : 
mul_preserves_le, 
absval_wf, 
nat_wf, 
absval-non-neg, 
le_wf, 
squash_wf, 
true_wf, 
decidable__equal_int, 
multiply-is-int-iff, 
satisfiable-full-omega-tt, 
intformnot_wf, 
intformeq_wf, 
itermConstant_wf, 
itermMultiply_wf, 
itermVar_wf, 
int_formula_prop_not_lemma, 
int_formula_prop_eq_lemma, 
int_term_value_constant_lemma, 
int_term_value_mul_lemma, 
int_term_value_var_lemma, 
int_formula_prop_wf, 
false_wf, 
lt_int_wf, 
bool_wf, 
eqtt_to_assert, 
assert_of_lt_int, 
top_wf, 
less_than_wf, 
eqff_to_assert, 
equal_wf, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
itermMinus_wf, 
int_term_value_minus_lemma, 
absval_unfold
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
natural_numberEquality, 
hypothesisEquality, 
hypothesis, 
applyEquality, 
lambdaEquality, 
setElimination, 
rename, 
sqequalRule, 
independent_isectElimination, 
because_Cache, 
hyp_replacement, 
equalitySymmetry, 
imageElimination, 
equalityTransitivity, 
intEquality, 
dependent_functionElimination, 
unionElimination, 
pointwiseFunctionality, 
promote_hyp, 
productElimination, 
baseApply, 
closedConclusion, 
baseClosed, 
dependent_pairFormation, 
int_eqEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
computeAll, 
imageMemberEquality, 
minusEquality, 
equalityElimination, 
lessCases, 
isect_memberFormation, 
sqequalAxiom, 
independent_pairFormation, 
independent_functionElimination, 
multiplyEquality, 
instantiate, 
cumulativity
Latex:
\mforall{}x:\mBbbZ{}.  (0  \mleq{}  (x  *  x))
Date html generated:
2017_04_14-AM-09_15_33
Last ObjectModification:
2017_02_27-PM-03_53_21
Theory : int_2
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