Nuprl Lemma : rational-truncate

q:ℚ. ∀e:{e:ℚ0 < e} .  (∃q':ℚ [(|q q'| ≤ e)])


Proof




Definitions occuring in Statement :  qabs: |r| qle: r ≤ s qless: r < s qsub: s rationals: all: x:A. B[x] sq_exists: x:A [B[x]] set: {x:A| B[x]}  natural_number: $n
Definitions unfolded in proof :  all: x:A. B[x] sq_exists: x:A [B[x]] member: t ∈ T prop: uall: [x:A]. B[x] so_lambda: λ2x.t[x] subtype_rel: A ⊆B so_apply: x[s] implies:  Q bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a guard: {T} iff: ⇐⇒ Q ifthenelse: if then else fi  bfalse: ff exists: x:A. B[x] or: P ∨ Q sq_type: SQType(T) bnot: ¬bb assert: b false: False squash: T true: True pi1: fst(t) cand: c∧ B pi2: snd(t) nat_plus: + int_nzero: -o nequal: a ≠ b ∈  not: ¬A satisfiable_int_formula: satisfiable_int_formula(fmla) top: Top mk-rational: mk-rational(a;b) sq_stable: SqStable(P) rev_implies:  Q qsub: s
Lemmas referenced :  set_wf rationals_wf qless_wf int-subtype-rationals q_less_wf bool_wf eqtt_to_assert assert-q_less-eq iff_weakening_equal eqff_to_assert equal_wf bool_cases_sqequal subtype_base_sq bool_subtype_base assert-bnot not_wf squash_wf true_wf rational-truncate1 all_wf sq_exists_wf nat_plus_wf qle_wf qabs_wf qsub_wf qdiv_wf subtype_rel_set less_than_wf int_nzero-rational subtype_rel_sets nequal_wf nat_plus_properties satisfiable-full-omega-tt intformand_wf intformeq_wf itermVar_wf itermConstant_wf intformless_wf int_formula_prop_and_lemma int_formula_prop_eq_lemma int_term_value_var_lemma int_term_value_constant_lemma int_formula_prop_less_lemma int_formula_prop_wf equal-wf-base int_subtype_base qmul_wf subtype_rel_transitivity int_nzero_wf mk-rational_wf integer-part_wf sq_stable_from_decidable decidable__qle qdiv-int-elim fractional-part_wf integer-fractional-parts mon_assoc_q qadd_ac_1_q qadd_wf qinverse_q mon_ident_q qless_complement_qorder qabs-of-nonneg qless_transitivity_2_qorder qle_weakening_lt_qorder
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation dependent_set_memberFormation cut introduction extract_by_obid sqequalHypSubstitution isectElimination thin hypothesis sqequalRule lambdaEquality natural_numberEquality applyEquality hypothesisEquality setElimination rename because_Cache unionElimination equalityElimination equalityTransitivity equalitySymmetry productElimination independent_isectElimination independent_functionElimination dependent_pairFormation promote_hyp dependent_functionElimination instantiate cumulativity voidElimination imageElimination universeEquality imageMemberEquality baseClosed setEquality productEquality intEquality applyLambdaEquality int_eqEquality isect_memberEquality voidEquality independent_pairFormation computeAll functionExtensionality dependent_set_memberEquality independent_pairEquality minusEquality

Latex:
\mforall{}q:\mBbbQ{}.  \mforall{}e:\{e:\mBbbQ{}|  0  <  e\}  .    (\mexists{}q':\mBbbQ{}  [(|q  -  q'|  \mleq{}  e)])



Date html generated: 2018_05_22-AM-00_31_22
Last ObjectModification: 2017_07_26-PM-06_58_59

Theory : rationals


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