Nuprl Lemma : Machin-formula
π = ((r(16) * arctangent((r1/r(5)))) - r(4) * arctangent((r1/r(239))))
Proof
Definitions occuring in Statement : 
arctangent: arctangent(x), 
pi: π, 
rdiv: (x/y), 
rsub: x - y, 
req: x = y, 
rmul: a * b, 
int-to-real: r(n), 
natural_number: $n
Definitions unfolded in proof : 
member: t ∈ T, 
uall: ∀[x:A]. B[x], 
uimplies: b supposing a, 
rneq: x ≠ y, 
guard: {T}, 
or: P ∨ Q, 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
rev_implies: P ⇐ Q, 
implies: P ⇒ Q, 
less_than: a < b, 
squash: ↓T, 
less_than': less_than'(a;b), 
true: True, 
prop: ℙ, 
uiff: uiff(P;Q), 
rdiv: (x/y), 
req_int_terms: t1 ≡ t2, 
false: False, 
not: ¬A, 
top: Top
Lemmas referenced : 
Machin-lemma, 
arctangent_wf, 
rdiv_wf, 
int-to-real_wf, 
rless-int, 
rless_wf, 
real_wf, 
req_wf, 
pi_wf, 
rsub_wf, 
rmul_wf, 
equal_wf, 
rmul_preserves_req, 
radd_wf, 
rinv_wf2, 
itermSubtract_wf, 
itermMultiply_wf, 
itermVar_wf, 
itermConstant_wf, 
req-iff-rsub-is-0, 
itermAdd_wf, 
req-implies-req, 
req_functionality, 
req_transitivity, 
rmul-rinv3, 
real_polynomial_null, 
real_term_value_sub_lemma, 
real_term_value_mul_lemma, 
real_term_value_var_lemma, 
real_term_value_const_lemma, 
real_term_value_add_lemma
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
thin, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
sqequalHypSubstitution, 
isectElimination, 
natural_numberEquality, 
hypothesis, 
independent_isectElimination, 
sqequalRule, 
inrFormation, 
dependent_functionElimination, 
because_Cache, 
productElimination, 
independent_functionElimination, 
independent_pairFormation, 
imageMemberEquality, 
hypothesisEquality, 
baseClosed, 
lambdaFormation, 
equalityTransitivity, 
equalitySymmetry, 
minusEquality, 
approximateComputation, 
lambdaEquality, 
int_eqEquality, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality
Latex:
\mpi{}  =  ((r(16)  *  arctangent((r1/r(5))))  -  r(4)  *  arctangent((r1/r(239))))
Date html generated:
2018_05_22-PM-03_03_51
Last ObjectModification:
2017_10_22-PM-05_56_36
Theory : reals_2
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