Nuprl Lemma : better-gcd-gcd

[y,x:ℤ].  (better-gcd(x;y) gcd(x;y))


Proof




Definitions occuring in Statement :  better-gcd: better-gcd(a;b) gcd: gcd(a;b) uall: [x:A]. B[x] int: sqequal: t
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a sq_type: SQType(T) all: x:A. B[x] implies:  Q guard: {T} nat: false: False ge: i ≥  prop: subtype_rel: A ⊆B decidable: Dec(P) or: P ∨ Q iff: ⇐⇒ Q and: P ∧ Q not: ¬A rev_implies:  Q uiff: uiff(P;Q) subtract: m top: Top le: A ≤ B less_than': less_than'(a;b) true: True has-value: (a)↓ nequal: a ≠ b ∈  gcd: gcd(a;b) bool: 𝔹 unit: Unit it: btrue: tt ifthenelse: if then else fi  bfalse: ff better-gcd: better-gcd(a;b) int_nzero: -o squash: T
Lemmas referenced :  subtype_base_sq int_subtype_base nat_properties less_than_transitivity1 less_than_irreflexivity ge_wf less_than_wf absval_wf decidable__le subtract_wf istype-false not-ge-2 less-iff-le condition-implies-le minus-one-mul zero-add minus-one-mul-top istype-void minus-add minus-minus add-associates add-swap add-commutes add_functionality_wrt_le add-zero le-add-cancel nat_wf absval-non-neg eq_int_wf equal-wf-base bool_wf assert_wf bnot_wf not_wf value-type-has-value int-value-type uiff_transitivity eqtt_to_assert assert_of_eq_int iff_transitivity iff_weakening_uiff eqff_to_assert assert_of_bnot rem_bounds_z nequal_wf equal_wf squash_wf true_wf decidable__lt not-lt-2 gcd_wf subtype_rel_self iff_weakening_equal zero-mul add-mul-special false_wf le_wf not-le-2
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity Error :isect_memberFormation_alt,  introduction cut thin instantiate extract_by_obid sqequalHypSubstitution isectElimination cumulativity intEquality independent_isectElimination hypothesis dependent_functionElimination equalityTransitivity equalitySymmetry independent_functionElimination axiomSqEquality Error :inhabitedIsType,  hypothesisEquality sqequalRule Error :isect_memberEquality_alt,  Error :universeIsType,  Error :lambdaFormation_alt,  setElimination rename intWeakElimination natural_numberEquality voidElimination Error :lambdaEquality_alt,  axiomEquality applyEquality because_Cache unionElimination independent_pairFormation productElimination addEquality minusEquality baseApply closedConclusion baseClosed Error :equalityIsType3,  callbyvalueReduce remainderEquality equalityElimination Error :equalityIsType1,  Error :dependent_set_memberEquality_alt,  imageElimination universeEquality imageMemberEquality multiplyEquality voidEquality isect_memberEquality lambdaEquality lambdaFormation dependent_set_memberEquality

Latex:
\mforall{}[y,x:\mBbbZ{}].    (better-gcd(x;y)  \msim{}  gcd(x;y))



Date html generated: 2019_06_20-AM-11_25_31
Last ObjectModification: 2018_09_28-AM-11_57_29

Theory : arithmetic


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