Nuprl Lemma : rnonzero_functionality

x,y:ℝ.  ((x y)  (rnonzero(x) ⇐⇒ rnonzero(y)))


Proof




Definitions occuring in Statement :  rnonzero: rnonzero(x) req: y real: all: x:A. B[x] iff: ⇐⇒ Q implies:  Q
Definitions unfolded in proof :  all: x:A. B[x] implies:  Q member: t ∈ T prop: uall: [x:A]. B[x] real: rnonzero: rnonzero(x) exists: x:A. B[x] uimplies: supposing a nat_plus: + subtype_rel: A ⊆B nat: decidable: Dec(P) or: P ∨ Q less_than: a < b squash: T and: P ∧ Q satisfiable_int_formula: satisfiable_int_formula(fmla) false: False not: ¬A top: Top less_than': less_than'(a;b) true: True req: y le: A ≤ B uiff: uiff(P;Q) rev_uimplies: rev_uimplies(P;Q) ge: i ≥  guard: {T} iff: ⇐⇒ Q rev_implies:  Q
Lemmas referenced :  rnonzero_wf req_wf real_wf rnonzero-lemma1 nat_plus_properties decidable__le absval_wf less_than_wf nat_wf satisfiable-full-omega-tt intformand_wf intformnot_wf intformle_wf itermConstant_wf itermVar_wf intformless_wf int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_le_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_less_lemma int_formula_prop_wf mul_nat_plus itermMultiply_wf int_term_value_mul_lemma subtract_wf multiply-is-int-iff false_wf decidable__equal_int intformeq_wf itermAdd_wf itermSubtract_wf int_formula_prop_eq_lemma int_term_value_add_lemma int_term_value_subtract_lemma and_wf equal_wf le_wf le_functionality le_weakening int-triangle-inequality mul_cancel_in_le decidable__lt add-is-int-iff req_inversion
Rules used in proof :  cut sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation introduction extract_by_obid sqequalHypSubstitution isectElimination thin setElimination rename hypothesisEquality hypothesis productElimination independent_isectElimination dependent_functionElimination natural_numberEquality applyEquality dependent_set_memberEquality lambdaEquality sqequalRule unionElimination imageElimination dependent_pairFormation int_eqEquality intEquality isect_memberEquality voidElimination voidEquality independent_pairFormation computeAll imageMemberEquality baseClosed because_Cache independent_functionElimination multiplyEquality addEquality pointwiseFunctionality equalityTransitivity equalitySymmetry promote_hyp baseApply closedConclusion setEquality hyp_replacement Error :applyLambdaEquality

Latex:
\mforall{}x,y:\mBbbR{}.    ((x  =  y)  {}\mRightarrow{}  (rnonzero(x)  \mLeftarrow{}{}\mRightarrow{}  rnonzero(y)))



Date html generated: 2016_10_26-AM-09_04_12
Last ObjectModification: 2016_07_12-AM-08_14_38

Theory : reals


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