Nuprl Lemma : combine-rless

∀a,b,c,d:ℝ.  ((a < b) ⇒ (c < d) ⇒ (((b * c) + (a * d)) < ((b * d) + (a * c))))


Proof




Definitions occuring in Statement :  rless: x < y,  rmul: a * b,  radd: a + b,  real: ℝ,  all: ∀x:A. B[x],  implies: P ⇒ Q
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q,  or: P ∨ Q,  cand: A c∧ B,  uimplies: b supposing a,  prop: ℙ,  uiff: uiff(P;Q),  req_int_terms: t1 ≡ t2,  false: False,  not: ¬A,  top: Top
Lemmas referenced :  rmul-is-positive,  rsub_wf,  rless-implies-rless,  int-to-real_wf,  rless_wf,  radd_wf,  rmul_wf,  real_wf,  itermSubtract_wf,  itermVar_wf,  itermConstant_wf,  req-iff-rsub-is-0,  itermMultiply_wf,  itermAdd_wf,  real_polynomial_null,  istype-int,  real_term_value_sub_lemma,  istype-void,  real_term_value_var_lemma,  real_term_value_const_lemma,  real_term_value_mul_lemma,  real_term_value_add_lemma
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  isectElimination,  hypothesisEquality,  hypothesis,  productElimination,  independent_functionElimination,  inlFormation_alt,  natural_numberEquality,  because_Cache,  independent_isectElimination,  independent_pairFormation,  sqequalRule,  productIsType,  universeIsType,  inhabitedIsType,  approximateComputation,  lambdaEquality_alt,  int_eqEquality,  isect_memberEquality_alt,  voidElimination

Latex:
\mforall{}a,b,c,d:\mBbbR{}.    ((a  <  b)  {}\mRightarrow{}  (c  <  d)  {}\mRightarrow{}  (((b  *  c)  +  (a  *  d))  <  ((b  *  d)  +  (a  *  c))))



Date html generated: 2019_10_29-AM-10_05_29
Last ObjectModification: 2019_04_09-AM-10_58_54

Theory : reals


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