Nuprl Lemma : cheap-real-upper-bound
∀[x:ℝ]. (x ≤ r((((x 1) + 1) ÷ 2) + 1))
Proof
Definitions occuring in Statement : 
rleq: x ≤ y
, 
int-to-real: r(n)
, 
real: ℝ
, 
uall: ∀[x:A]. B[x]
, 
apply: f a
, 
divide: n ÷ m
, 
add: n + m
, 
natural_number: $n
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
nat_plus: ℕ+
, 
all: ∀x:A. B[x]
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
uimplies: b supposing a
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
top: Top
, 
prop: ℙ
, 
false: False
Lemmas referenced : 
real-upper-bound, 
decidable__lt, 
full-omega-unsat, 
intformnot_wf, 
intformless_wf, 
itermConstant_wf, 
istype-int, 
int_formula_prop_not_lemma, 
istype-void, 
int_formula_prop_less_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_wf, 
istype-less_than, 
mul-commutes, 
real_wf
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
dependent_set_memberEquality_alt, 
natural_numberEquality, 
dependent_functionElimination, 
unionElimination, 
independent_isectElimination, 
approximateComputation, 
independent_functionElimination, 
dependent_pairFormation_alt, 
lambdaEquality_alt, 
isect_memberEquality_alt, 
voidElimination, 
sqequalRule, 
universeIsType
Latex:
\mforall{}[x:\mBbbR{}].  (x  \mleq{}  r((((x  1)  +  1)  \mdiv{}  2)  +  1))
Date html generated:
2019_10_31-AM-06_10_43
Last ObjectModification:
2019_01_30-PM-02_03_09
Theory : reals_2
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