Nuprl Lemma : rmax-nonneg

[x,y:ℝ].  rnonneg(rmax(x;y)) supposing rnonneg(x) ∨ rnonneg(y)


Proof




Definitions occuring in Statement :  rnonneg: rnonneg(x) rmax: rmax(x;y) real: uimplies: supposing a uall: [x:A]. B[x] or: P ∨ Q
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a all: x:A. B[x] implies:  Q rnonneg: rnonneg(x) le: A ≤ B and: P ∧ Q not: ¬A false: False subtype_rel: A ⊆B real: prop: or: P ∨ Q rnonneg2: rnonneg2(x) exists: x:A. B[x] rmax: rmax(x;y) squash: T nat_plus: + true: True guard: {T} iff: ⇐⇒ Q rev_implies:  Q int_upper: {i...} bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) ifthenelse: if then else fi  bfalse: ff sq_type: SQType(T) bnot: ¬bb assert: b so_lambda: λ2x.t[x] so_apply: x[s] decidable: Dec(P) satisfiable_int_formula: satisfiable_int_formula(fmla) top: Top
Lemmas referenced :  less_than'_wf rmax_wf real_wf nat_plus_wf or_wf rnonneg_wf le_wf squash_wf true_wf imax_unfold iff_weakening_equal le_int_wf less_than_transitivity1 less_than_wf bool_wf eqtt_to_assert assert_of_le_int eqff_to_assert equal_wf bool_cases_sqequal subtype_base_sq bool_subtype_base assert-bnot int_upper_wf all_wf rnonneg2_wf rnonneg-iff mul_preserves_le nat_plus_subtype_nat int_upper_properties nat_plus_properties decidable__le satisfiable-full-omega-tt intformand_wf intformnot_wf intformle_wf itermMultiply_wf itermConstant_wf itermVar_wf int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_le_lemma int_term_value_mul_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_wf mul_cancel_in_le multiply-is-int-iff false_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut thin sqequalHypSubstitution dependent_functionElimination hypothesisEquality hypothesis independent_functionElimination sqequalRule lambdaEquality productElimination independent_pairEquality because_Cache extract_by_obid isectElimination applyEquality setElimination rename minusEquality natural_numberEquality axiomEquality equalityTransitivity equalitySymmetry isect_memberEquality voidElimination lambdaFormation unionElimination dependent_pairFormation imageElimination intEquality multiplyEquality imageMemberEquality baseClosed universeEquality independent_isectElimination dependent_set_memberEquality equalityElimination promote_hyp instantiate cumulativity addLevel impliesFunctionality orFunctionality orLevelFunctionality functionEquality int_eqEquality voidEquality independent_pairFormation computeAll pointwiseFunctionality baseApply closedConclusion

Latex:
\mforall{}[x,y:\mBbbR{}].    rnonneg(rmax(x;y))  supposing  rnonneg(x)  \mvee{}  rnonneg(y)



Date html generated: 2017_10_03-AM-08_24_26
Last ObjectModification: 2017_07_28-AM-07_23_20

Theory : reals


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