Nuprl Lemma : rtan_one_one
∀x,y:{x:ℝ| x ∈ (-(π/2), π/2)} .  x = y supposing rtan(x) = rtan(y)
Proof
Definitions occuring in Statement : 
rtan: rtan(x)
, 
halfpi: π/2
, 
rooint: (l, u)
, 
i-member: r ∈ I
, 
req: x = y
, 
rminus: -(x)
, 
real: ℝ
, 
uimplies: b supposing a
, 
all: ∀x:A. B[x]
, 
set: {x:A| B[x]} 
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
implies: P 
⇒ Q
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
rneq: x ≠ y
, 
or: P ∨ Q
, 
guard: {T}
, 
false: False
, 
stable: Stable{P}
, 
not: ¬A
Lemmas referenced : 
req_witness, 
req_wf, 
rtan_wf, 
i-member_wf, 
rooint_wf, 
rminus_wf, 
halfpi_wf, 
set_wf, 
real_wf, 
stable_req, 
false_wf, 
or_wf, 
rneq_wf, 
not_wf, 
rtan_functionality_wrt_rless, 
req_inversion, 
rless_transitivity1, 
rleq_weakening, 
rless_irreflexivity, 
not-rneq, 
minimal-double-negation-hyp-elim, 
minimal-not-not-excluded-middle
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
isect_memberFormation, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
setElimination, 
rename, 
hypothesisEquality, 
hypothesis, 
independent_functionElimination, 
dependent_functionElimination, 
dependent_set_memberEquality, 
because_Cache, 
sqequalRule, 
lambdaEquality, 
functionEquality, 
unionElimination, 
independent_isectElimination, 
voidElimination
Latex:
\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  (-(\mpi{}/2),  \mpi{}/2)\}  .    x  =  y  supposing  rtan(x)  =  rtan(y)
Date html generated:
2018_05_22-PM-02_59_46
Last ObjectModification:
2017_10_22-PM-08_21_36
Theory : reals_2
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