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: x = y,  radd: a + b,  int-to-real: r(n),  nat_plus: ℕ+,  uall: ∀[x:A]. B[x],  multiply: n * m,  add: n + m,  int: ℤ
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  nat_plus: ℕ+,  uimplies: b supposing a,  rneq: x ≠ y,  guard: {T},  or: P ∨ Q,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q,  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  not: ¬A,  top: Top,  prop: ℙ,  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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