Nuprl Lemma : arctangent1
arctangent(r1) = (π/r(4))
Proof
Definitions occuring in Statement : 
arctangent: arctangent(x), 
pi: π, 
rdiv: (x/y), 
req: x = y, 
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, 
cand: A c∧ B, 
rminus: -(x), 
halfpi: π/2, 
cubic_converge: cubic_converge(b;m), 
ifthenelse: if b then t else f fi , 
le_int: i ≤z j, 
bnot: ¬bb, 
lt_int: i <z j, 
bfalse: ff, 
btrue: tt, 
fastpi: fastpi(n), 
primrec: primrec(n;b;c), 
rdiv: (x/y), 
rmul: a * b, 
pi: π, 
int-rmul: k1 * a, 
rinv: rinv(x), 
mu-ge: mu-ge(f;n), 
int-to-real: r(n), 
absval: |i|, 
eq_int: (i =z j), 
accelerate: accelerate(k;f), 
imax: imax(a;b), 
canonical-bound: canonical-bound(r), 
reg-seq-inv: reg-seq-inv(x), 
reg-seq-mul: reg-seq-mul(x;y), 
subtype_rel: A ⊆r B, 
real: ℝ, 
nat_plus: ℕ+, 
rless: x < y, 
sq_exists: ∃x:A [B[x]], 
top: Top, 
uiff: uiff(P;Q), 
rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced : 
rdiv_wf, 
pi_wf, 
int-to-real_wf, 
rless-int, 
rless_wf, 
rminus_wf, 
halfpi_wf, 
real_wf, 
less_than_wf, 
arctangent_wf, 
rtan_wf, 
member_rooint_lemma, 
arctangent-rtan, 
req_functionality, 
arctangent_functionality, 
req_inversion, 
rtan-pi-over-4, 
req_weakening
Rules used in proof : 
cut, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
dependent_set_memberEquality, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesis, 
natural_numberEquality, 
independent_isectElimination, 
sqequalRule, 
inrFormation, 
dependent_functionElimination, 
because_Cache, 
productElimination, 
independent_functionElimination, 
independent_pairFormation, 
imageMemberEquality, 
hypothesisEquality, 
baseClosed, 
addEquality, 
applyEquality, 
lambdaEquality, 
setElimination, 
rename, 
productEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality
Latex:
arctangent(r1)  =  (\mpi{}/r(4))
Date html generated:
2018_05_22-PM-03_03_56
Last ObjectModification:
2017_10_22-PM-08_10_28
Theory : reals_2
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