Nuprl Lemma : radd-int-fractions

[a,b:ℤ]. ∀[c,d:ℕ+].  (((r(a)/r(c)) (r(b)/r(d))) (r((a d) (b c))/r(c d)))


Proof




Definitions occuring in Statement :  rdiv: (x/y) req: y radd: b int-to-real: r(n) nat_plus: + uall: [x:A]. B[x] multiply: m add: m int:
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T nat_plus: + uimplies: supposing a rneq: x ≠ y guard: {T} or: P ∨ Q all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q implies:  Q decidable: Dec(P) satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False not: ¬A top: Top prop: uiff: uiff(P;Q) rev_uimplies: rev_uimplies(P;Q) itermConstant: "const" req_int_terms: t1 ≡ t2 rdiv: (x/y)
Lemmas referenced :  req_witness radd_wf rdiv_wf int-to-real_wf rless-int nat_plus_properties decidable__lt satisfiable-full-omega-tt intformand_wf intformnot_wf intformless_wf itermConstant_wf itermVar_wf int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_less_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_wf rless_wf mul_bounds_1b nat_plus_wf rmul_wf rneq_functionality rmul-int req_weakening rmul_preserves_req req_wf rinv_wf2 real_term_polynomial itermSubtract_wf itermMultiply_wf itermAdd_wf real_term_value_const_lemma real_term_value_sub_lemma real_term_value_mul_lemma real_term_value_add_lemma real_term_value_var_lemma req-iff-rsub-is-0 uiff_transitivity req_functionality rmul_functionality rdiv_functionality req_transitivity req_inversion radd-int radd_functionality rinv-of-rmul rmul-rinv rmul-rinv3 rmul-int-rdiv
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis setElimination rename because_Cache independent_isectElimination sqequalRule inrFormation dependent_functionElimination productElimination independent_functionElimination natural_numberEquality unionElimination dependent_pairFormation lambdaEquality int_eqEquality intEquality isect_memberEquality voidElimination voidEquality independent_pairFormation computeAll addEquality multiplyEquality

Latex:
\mforall{}[a,b:\mBbbZ{}].  \mforall{}[c,d:\mBbbN{}\msupplus{}].    (((r(a)/r(c))  +  (r(b)/r(d)))  =  (r((a  *  d)  +  (b  *  c))/r(c  *  d)))



Date html generated: 2017_10_03-AM-08_38_00
Last ObjectModification: 2017_07_28-AM-07_30_25

Theory : reals


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