Nuprl Lemma : q-square-positive

∀[q:ℚ]. 0 < q * q supposing ¬(q = 0 ∈ ℚ)


Proof




Definitions occuring in Statement :  qless: r < s,  qmul: r * s,  rationals: ℚ,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  not: ¬A,  natural_number: $n,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  subtype_rel: A ⊆r B,  implies: P ⇒ Q,  prop: ℙ,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  or: P ∨ Q,  not: ¬A,  false: False,  rev_implies: P ⇐ Q
Lemmas referenced :  q-square-non-neg,  qless_witness,  qmul_wf,  not_wf,  equal_wf,  rationals_wf,  qle_iff_lt_or_eq_qorder,  int-subtype-rationals,  qmul-zero
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  lemma_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  natural_numberEquality,  hypothesis,  applyEquality,  because_Cache,  sqequalRule,  independent_functionElimination,  isect_memberEquality,  equalityTransitivity,  equalitySymmetry,  dependent_functionElimination,  productElimination,  unionElimination,  voidElimination

Latex:
\mforall{}[q:\mBbbQ{}].  0  <  q  *  q  supposing  \mneg{}(q  =  0)



Date html generated: 2016_05_15-PM-10_59_02
Last ObjectModification: 2015_12_27-PM-07_51_06

Theory : rationals


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