Nuprl Lemma : rleq-implies-rleq

[a,b,c,d:ℝ].  (a ≤ b) supposing ((c ≤ d) and ((d c) (b a)))


Proof




Definitions occuring in Statement :  rleq: x ≤ y rsub: y req: y real: uimplies: supposing a uall: [x:A]. B[x]
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a uiff: uiff(P;Q) and: P ∧ Q rev_uimplies: rev_uimplies(P;Q) rleq: x ≤ y rnonneg: rnonneg(x) all: x:A. B[x] le: A ≤ B not: ¬A implies:  Q false: False subtype_rel: A ⊆B real: prop: rsub: y guard: {T}
Lemmas referenced :  radd-preserves-rleq rminus_wf radd-rminus-both less_than'_wf rsub_wf real_wf nat_plus_wf rleq_wf req_wf radd_wf int-to-real_wf rleq_functionality req_weakening radd_comm req_inversion rleq_transitivity rleq_weakening
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis productElimination independent_isectElimination sqequalRule lambdaEquality dependent_functionElimination independent_pairEquality because_Cache applyEquality setElimination rename minusEquality natural_numberEquality axiomEquality equalityTransitivity equalitySymmetry isect_memberEquality voidElimination

Latex:
\mforall{}[a,b,c,d:\mBbbR{}].    (a  \mleq{}  b)  supposing  ((c  \mleq{}  d)  and  ((d  -  c)  =  (b  -  a)))



Date html generated: 2017_10_03-AM-08_25_39
Last ObjectModification: 2017_04_04-PM-02_19_18

Theory : reals


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