Nuprl Lemma : rabs-of-nonpos

∀[x:ℝ]. |x| = -(x) supposing x ≤ r0


Proof




Definitions occuring in Statement :  rleq: x ≤ y,  rabs: |x|,  req: x = y,  rminus: -(x),  int-to-real: r(n),  real: ℝ,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  natural_number: $n
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  top: Top,  uiff: uiff(P;Q),  and: P ∧ Q,  rev_uimplies: rev_uimplies(P;Q),  all: ∀x:A. B[x],  itermConstant: "const",  req_int_terms: t1 ≡ t2,  false: False,  implies: P ⇒ Q,  not: ¬A,  prop: ℙ,  guard: {T}
Lemmas referenced :  rabs-as-rmax,  rmax-req,  rminus_wf,  radd-preserves-rleq,  rleq_functionality,  radd_wf,  rmul_wf,  int-to-real_wf,  real_term_polynomial,  itermSubtract_wf,  itermAdd_wf,  itermVar_wf,  itermMultiply_wf,  itermConstant_wf,  real_term_value_const_lemma,  real_term_value_sub_lemma,  real_term_value_add_lemma,  real_term_value_var_lemma,  real_term_value_mul_lemma,  req-iff-rsub-is-0,  itermMinus_wf,  real_term_value_minus_lemma,  req_witness,  rabs_wf,  rleq_wf,  real_wf,  rleq_transitivity,  req_transitivity,  rmul-identity1
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalRule,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  isect_memberEquality,  voidElimination,  voidEquality,  hypothesis,  hypothesisEquality,  independent_isectElimination,  because_Cache,  productElimination,  natural_numberEquality,  dependent_functionElimination,  computeAll,  lambdaEquality,  int_eqEquality,  intEquality,  independent_functionElimination,  equalityTransitivity,  equalitySymmetry

Latex:
\mforall{}[x:\mBbbR{}].  |x|  =  -(x)  supposing  x  \mleq{}  r0



Date html generated: 2017_10_03-AM-08_30_52
Last ObjectModification: 2017_07_28-AM-07_26_49

Theory : reals


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