Nuprl Lemma : rmul_preserves_rleq3

∀[x,y,a,b:ℝ].  ((x * y) ≤ (a * b)) supposing ((x ≤ a) and (y ≤ b) and ((r0 ≤ x) ∧ (r0 ≤ y)))


Proof




Definitions occuring in Statement :  rleq: x ≤ y,  rmul: a * b,  int-to-real: r(n),  real: ℝ,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  and: P ∧ Q,  natural_number: $n
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  and: P ∧ Q,  guard: {T},  rleq: x ≤ y,  rnonneg: rnonneg(x),  all: ∀x:A. B[x],  le: A ≤ B,  prop: ℙ,  uiff: uiff(P;Q),  req_int_terms: t1 ≡ t2,  false: False,  implies: P ⇒ Q,  not: ¬A,  top: Top,  rev_uimplies: rev_uimplies(P;Q),  rge: x ≥ y
Lemmas referenced :  rmul_preserves_rleq2,  rleq_transitivity,  int-to-real_wf,  le_witness_for_triv,  rleq_wf,  real_wf,  rmul_wf,  itermSubtract_wf,  itermMultiply_wf,  itermVar_wf,  rleq_functionality,  req-iff-rsub-is-0,  real_polynomial_null,  istype-int,  real_term_value_sub_lemma,  istype-void,  real_term_value_mul_lemma,  real_term_value_var_lemma,  real_term_value_const_lemma,  rleq_functionality_wrt_implies,  rleq_weakening_equal
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  sqequalHypSubstitution,  productElimination,  thin,  extract_by_obid,  isectElimination,  hypothesisEquality,  independent_isectElimination,  hypothesis,  natural_numberEquality,  promote_hyp,  sqequalRule,  lambdaEquality_alt,  dependent_functionElimination,  equalityTransitivity,  equalitySymmetry,  functionIsTypeImplies,  inhabitedIsType,  universeIsType,  isect_memberEquality_alt,  isectIsTypeImplies,  productIsType,  because_Cache,  approximateComputation,  int_eqEquality,  voidElimination

Latex:
\mforall{}[x,y,a,b:\mBbbR{}].    ((x  *  y)  \mleq{}  (a  *  b))  supposing  ((x  \mleq{}  a)  and  (y  \mleq{}  b)  and  ((r0  \mleq{}  x)  \mwedge{}  (r0  \mleq{}  y)))



Date html generated: 2019_10_29-AM-09_38_11
Last ObjectModification: 2019_02_04-AM-10_02_05

Theory : reals


Home Index