Nuprl Lemma : divides-iff-gcd
∀x,y:ℤ.  (x | y ⇐⇒ gcd(y;x) = x ∈ ℤ)
Proof
Definitions occuring in Statement : 
divides: b | a, 
gcd: gcd(a;b), 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
int: ℤ, 
equal: s = t ∈ T
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
implies: P ⇒ Q, 
member: t ∈ T, 
prop: ℙ, 
uall: ∀[x:A]. B[x], 
rev_implies: P ⇐ Q, 
subtype_rel: A ⊆r B, 
gcd: gcd(a;b), 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
uimplies: b supposing a, 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
not: ¬A, 
divides: b | a, 
exists: ∃x:A. B[x], 
sq_type: SQType(T), 
guard: {T}, 
decidable: Dec(P), 
or: P ∨ Q, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
false: False, 
top: Top, 
nequal: a ≠ b ∈ T , 
int_nzero: ℤ-o, 
squash: ↓T, 
true: True
Lemmas referenced : 
divides_wf, 
equal-wf-base, 
int_subtype_base, 
eq_int_wf, 
bool_wf, 
assert_wf, 
bnot_wf, 
not_wf, 
uiff_transitivity, 
eqtt_to_assert, 
assert_of_eq_int, 
iff_transitivity, 
iff_weakening_uiff, 
eqff_to_assert, 
assert_of_bnot, 
equal_wf, 
subtype_base_sq, 
decidable__equal_int, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformnot_wf, 
intformeq_wf, 
itermVar_wf, 
itermConstant_wf, 
itermMultiply_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_eq_lemma, 
int_term_value_var_lemma, 
int_term_value_constant_lemma, 
int_term_value_mul_lemma, 
int_formula_prop_wf, 
divides_iff_rem_zero, 
nequal_wf, 
gcd_is_divisor_1, 
squash_wf, 
true_wf, 
iff_weakening_equal
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
independent_pairFormation, 
cut, 
hypothesis, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
intEquality, 
sqequalRule, 
baseApply, 
closedConclusion, 
baseClosed, 
applyEquality, 
because_Cache, 
natural_numberEquality, 
equalityTransitivity, 
equalitySymmetry, 
unionElimination, 
equalityElimination, 
independent_functionElimination, 
productElimination, 
independent_isectElimination, 
impliesFunctionality, 
dependent_functionElimination, 
instantiate, 
cumulativity, 
dependent_pairFormation, 
lambdaEquality, 
int_eqEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
computeAll, 
remainderEquality, 
dependent_set_memberEquality, 
imageElimination, 
imageMemberEquality, 
universeEquality
Latex:
\mforall{}x,y:\mBbbZ{}.    (x  |  y  \mLeftarrow{}{}\mRightarrow{}  gcd(y;x)  =  x)
Date html generated:
2018_05_21-PM-01_10_19
Last ObjectModification:
2018_01_28-PM-02_03_46
Theory : num_thy_1
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