Nuprl Lemma : gcd_wf

a,b:ℤ.  (gcd(a;b) ∈ ℤ)


Proof




Definitions occuring in Statement :  gcd: gcd(a;b) all: x:A. B[x] member: t ∈ T int:
Definitions unfolded in proof :  all: x:A. B[x] uall: [x:A]. B[x] member: t ∈ T nat: implies:  Q false: False ge: i ≥  guard: {T} uimplies: supposing a prop: subtype_rel: A ⊆B le: A ≤ B and: P ∧ Q decidable: Dec(P) or: P ∨ Q iff: ⇐⇒ Q not: ¬A rev_implies:  Q uiff: uiff(P;Q) subtract: m top: Top less_than': less_than'(a;b) true: True gcd: gcd(a;b) bool: 𝔹 unit: Unit it: btrue: tt ifthenelse: if then else fi  bfalse: ff exists: x:A. B[x] sq_type: SQType(T) bnot: ¬bb assert: b nequal: a ≠ b ∈  int_nzero: -o
Lemmas referenced :  nat_properties less_than_transitivity1 less_than_irreflexivity ge_wf less_than_wf absval_wf nat_wf absval-non-neg decidable__le subtract_wf false_wf not-ge-2 less-iff-le condition-implies-le minus-one-mul zero-add minus-one-mul-top minus-add minus-minus add-associates add-swap add-commutes add_functionality_wrt_le add-zero le-add-cancel eq_int_wf bool_wf eqtt_to_assert assert_of_eq_int eqff_to_assert equal_wf bool_cases_sqequal subtype_base_sq bool_subtype_base iff_transitivity assert_wf bnot_wf not_wf equal-wf-base int_subtype_base iff_weakening_uiff assert_of_bnot rem_bounds_z nequal_wf decidable__lt not-lt-2 not-le-2 le_wf add-mul-special zero-mul
Rules used in proof :  cut sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation introduction extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis setElimination rename sqequalRule intWeakElimination natural_numberEquality independent_isectElimination independent_functionElimination voidElimination lambdaEquality dependent_functionElimination axiomEquality equalityTransitivity equalitySymmetry applyEquality intEquality productElimination because_Cache unionElimination independent_pairFormation addEquality isect_memberEquality voidEquality minusEquality equalityElimination dependent_pairFormation promote_hyp instantiate cumulativity baseClosed impliesFunctionality remainderEquality dependent_set_memberEquality multiplyEquality

Latex:
\mforall{}a,b:\mBbbZ{}.    (gcd(a;b)  \mmember{}  \mBbbZ{})



Date html generated: 2017_04_14-AM-07_18_48
Last ObjectModification: 2017_02_27-PM-02_52_44

Theory : arithmetic


Home Index