Nuprl Lemma : rabs-of-nonpos
∀[x:ℝ]. |x| = -(x) supposing x ≤ r0
Proof
Definitions occuring in Statement : 
rleq: x ≤ y
, 
rabs: |x|
, 
req: x = y
, 
rminus: -(x)
, 
int-to-real: r(n)
, 
real: ℝ
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
natural_number: $n
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
top: Top
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
rev_uimplies: rev_uimplies(P;Q)
, 
all: ∀x:A. B[x]
, 
itermConstant: "const"
, 
req_int_terms: t1 ≡ t2
, 
false: False
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
prop: ℙ
, 
guard: {T}
Lemmas referenced : 
rabs-as-rmax, 
rmax-req, 
rminus_wf, 
radd-preserves-rleq, 
rleq_functionality, 
radd_wf, 
rmul_wf, 
int-to-real_wf, 
real_term_polynomial, 
itermSubtract_wf, 
itermAdd_wf, 
itermVar_wf, 
itermMultiply_wf, 
itermConstant_wf, 
real_term_value_const_lemma, 
real_term_value_sub_lemma, 
real_term_value_add_lemma, 
real_term_value_var_lemma, 
real_term_value_mul_lemma, 
req-iff-rsub-is-0, 
itermMinus_wf, 
real_term_value_minus_lemma, 
req_witness, 
rabs_wf, 
rleq_wf, 
real_wf, 
rleq_transitivity, 
req_transitivity, 
rmul-identity1
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalRule, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
hypothesis, 
hypothesisEquality, 
independent_isectElimination, 
because_Cache, 
productElimination, 
natural_numberEquality, 
dependent_functionElimination, 
computeAll, 
lambdaEquality, 
int_eqEquality, 
intEquality, 
independent_functionElimination, 
equalityTransitivity, 
equalitySymmetry
Latex:
\mforall{}[x:\mBbbR{}].  |x|  =  -(x)  supposing  x  \mleq{}  r0
Date html generated:
2017_10_03-AM-08_30_52
Last ObjectModification:
2017_07_28-AM-07_26_49
Theory : reals
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