Nuprl Lemma : real-vec-triangle-inequality
∀[n:ℕ]. ∀[x,y,z:ℝ^n].  (d(x;z) ≤ (d(x;y) + d(y;z)))
Proof
Definitions occuring in Statement : 
real-vec-dist: d(x;y)
, 
real-vec: ℝ^n
, 
rleq: x ≤ y
, 
radd: a + b
, 
nat: ℕ
, 
uall: ∀[x:A]. B[x]
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
real-vec-dist: d(x;y)
, 
rleq: x ≤ y
, 
rnonneg: rnonneg(x)
, 
all: ∀x:A. B[x]
, 
le: A ≤ B
, 
and: P ∧ Q
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
false: False
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
real: ℝ
, 
rev_uimplies: rev_uimplies(P;Q)
, 
uimplies: b supposing a
, 
rge: x ≥ y
, 
guard: {T}
, 
req-vec: req-vec(n;x;y)
, 
real-vec-sub: X - Y
, 
real-vec-add: X + Y
, 
nat: ℕ
, 
real-vec: ℝ^n
, 
rsub: x - y
, 
uiff: uiff(P;Q)
Lemmas referenced : 
less_than'_wf, 
rsub_wf, 
radd_wf, 
real-vec-dist_wf, 
real_wf, 
rleq_wf, 
int-to-real_wf, 
nat_plus_wf, 
real-vec_wf, 
nat_wf, 
real-vec-norm_wf, 
real-vec-sub_wf, 
real-vec-add_wf, 
rleq_functionality_wrt_implies, 
rleq_weakening_equal, 
Minkowski-inequality1, 
real-vec-norm_functionality, 
int_seg_wf, 
req_wf, 
rminus_wf, 
req_weakening, 
uiff_transitivity, 
req_functionality, 
req_inversion, 
radd-assoc, 
radd_functionality, 
radd-ac, 
radd-rminus-assoc, 
rleq_weakening
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalRule, 
sqequalHypSubstitution, 
lambdaEquality, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
productElimination, 
independent_pairEquality, 
because_Cache, 
extract_by_obid, 
isectElimination, 
applyEquality, 
hypothesis, 
setElimination, 
rename, 
setEquality, 
natural_numberEquality, 
minusEquality, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
isect_memberEquality, 
voidElimination, 
independent_isectElimination, 
lambdaFormation, 
independent_functionElimination
Latex:
\mforall{}[n:\mBbbN{}].  \mforall{}[x,y,z:\mBbbR{}\^{}n].    (d(x;z)  \mleq{}  (d(x;y)  +  d(y;z)))
Date html generated:
2016_10_26-AM-10_27_25
Last ObjectModification:
2016_09_14-PM-06_48_45
Theory : reals
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