Nuprl Lemma : rminus-rminus

∀[x:ℝ]. (-(-(x)) = x)


Proof




Definitions occuring in Statement :  req: x = y,  rminus: -(x),  real: ℝ,  uall: ∀[x:A]. B[x]
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  real: ℝ,  rminus: -(x),  nat_plus: ℕ+,  all: ∀x:A. B[x],  decidable: Dec(P),  or: P ∨ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  implies: P ⇒ Q,  not: ¬A,  top: Top,  prop: ℙ,  guard: {T}
Lemmas referenced :  real_wf,  req_witness,  req_inversion,  regular-int-seq_wf,  nat_plus_wf,  int_formula_prop_wf,  int_term_value_minus_lemma,  int_term_value_var_lemma,  int_formula_prop_eq_lemma,  int_formula_prop_not_lemma,  itermMinus_wf,  itermVar_wf,  intformeq_wf,  intformnot_wf,  satisfiable-full-omega-tt,  decidable__equal_int,  nat_plus_properties,  rminus_wf,  req_weakening
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  lemma_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  hypothesis,  independent_isectElimination,  setElimination,  rename,  dependent_set_memberEquality,  functionExtensionality,  sqequalRule,  dependent_functionElimination,  because_Cache,  unionElimination,  natural_numberEquality,  dependent_pairFormation,  lambdaEquality,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  computeAll,  independent_functionElimination

Latex:
\mforall{}[x:\mBbbR{}].  (-(-(x))  =  x)



Date html generated: 2016_05_18-AM-06_51_09
Last ObjectModification: 2016_01_17-AM-01_46_06

Theory : reals


Home Index