Nuprl Lemma : gcd-positive
∀[y,x:ℕ].  (0 < gcd(x;y)) supposing ((0 ≤ y) and 0 < x)
Proof
Definitions occuring in Statement : 
gcd: gcd(a;b), 
nat: ℕ, 
less_than: a < b, 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
le: A ≤ B, 
natural_number: $n
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
all: ∀x:A. B[x], 
nat: ℕ, 
implies: P ⇒ Q, 
false: False, 
ge: i ≥ j , 
uimplies: b supposing a, 
not: ¬A, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
exists: ∃x:A. B[x], 
top: Top, 
and: P ∧ Q, 
prop: ℙ, 
guard: {T}, 
int_seg: {i..j-}, 
lelt: i ≤ j < k, 
le: A ≤ B, 
decidable: Dec(P), 
or: P ∨ Q, 
subtype_rel: A ⊆r B, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
sq_type: SQType(T), 
gcd: gcd(a;b), 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q, 
int_nzero: ℤ-o, 
nequal: a ≠ b ∈ T , 
nat_plus: ℕ+
Lemmas referenced : 
nat_properties, 
full-omega-unsat, 
intformand_wf, 
intformle_wf, 
itermConstant_wf, 
itermVar_wf, 
intformless_wf, 
istype-int, 
int_formula_prop_and_lemma, 
istype-void, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_term_value_var_lemma, 
int_formula_prop_less_lemma, 
int_formula_prop_wf, 
ge_wf, 
istype-less_than, 
member-less_than, 
int_seg_properties, 
int_seg_wf, 
subtract-1-ge-0, 
decidable__equal_int, 
subtract_wf, 
subtype_base_sq, 
set_subtype_base, 
int_subtype_base, 
intformnot_wf, 
intformeq_wf, 
itermSubtract_wf, 
int_formula_prop_not_lemma, 
int_formula_prop_eq_lemma, 
int_term_value_subtract_lemma, 
decidable__le, 
decidable__lt, 
istype-le, 
subtype_rel_self, 
eq_int_wf, 
uiff_transitivity, 
equal-wf-base, 
bool_wf, 
le_wf, 
assert_wf, 
eqtt_to_assert, 
assert_of_eq_int, 
iff_transitivity, 
bnot_wf, 
not_wf, 
iff_weakening_uiff, 
eqff_to_assert, 
assert_of_bnot, 
istype-assert, 
remainder_wfa, 
nequal_wf, 
rem_bounds_1, 
gcd_wf, 
itermAdd_wf, 
int_term_value_add_lemma, 
istype-nat
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
introduction, 
cut, 
thin, 
Error :lambdaFormation_alt, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
hypothesis, 
setElimination, 
rename, 
intWeakElimination, 
natural_numberEquality, 
independent_isectElimination, 
approximateComputation, 
independent_functionElimination, 
Error :dependent_pairFormation_alt, 
Error :lambdaEquality_alt, 
int_eqEquality, 
dependent_functionElimination, 
Error :isect_memberEquality_alt, 
voidElimination, 
sqequalRule, 
independent_pairFormation, 
Error :universeIsType, 
productElimination, 
Error :isectIsTypeImplies, 
Error :inhabitedIsType, 
Error :functionIsTypeImplies, 
because_Cache, 
unionElimination, 
applyEquality, 
instantiate, 
equalityTransitivity, 
equalitySymmetry, 
applyLambdaEquality, 
Error :dependent_set_memberEquality_alt, 
Error :productIsType, 
hypothesis_subsumption, 
equalityElimination, 
baseApply, 
closedConclusion, 
baseClosed, 
intEquality, 
Error :equalityIstype, 
sqequalBase, 
Error :functionIsType, 
addEquality
Latex:
\mforall{}[y,x:\mBbbN{}].    (0  <  gcd(x;y))  supposing  ((0  \mleq{}  y)  and  0  <  x)
Date html generated:
2019_06_20-PM-02_26_59
Last ObjectModification:
2019_03_06-AM-11_06_24
Theory : num_thy_1
Home
Index