Nuprl Lemma : rminus-rminus-eq
∀[x:ℝ]. (-(-(x)) = x ∈ ℝ)
Proof
Definitions occuring in Statement : 
rminus: -(x)
, 
real: ℝ
, 
uall: ∀[x:A]. B[x]
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
real: ℝ
, 
rminus: -(x)
, 
member: t ∈ T
, 
nat_plus: ℕ+
, 
all: ∀x:A. B[x]
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
uimplies: b supposing a
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
false: False
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
top: Top
, 
prop: ℙ
Lemmas referenced : 
real_wf, 
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
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
cut, 
equalitySymmetry, 
sqequalHypSubstitution, 
setElimination, 
thin, 
rename, 
dependent_set_memberEquality, 
functionExtensionality, 
sqequalRule, 
lemma_by_obid, 
isectElimination, 
hypothesisEquality, 
hypothesis, 
dependent_functionElimination, 
because_Cache, 
unionElimination, 
natural_numberEquality, 
independent_isectElimination, 
dependent_pairFormation, 
lambdaEquality, 
int_eqEquality, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
computeAll
Latex:
\mforall{}[x:\mBbbR{}].  (-(-(x))  =  x)
Date html generated:
2016_05_18-AM-06_51_12
Last ObjectModification:
2016_01_17-AM-01_46_04
Theory : reals
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