Nuprl Lemma : geo-add-length-lt-cancel-for-double
∀e:EuclideanPlane. ∀a,b:{a:Point| O_X_a} .  (a + a < b + b ⇒ a < b)
Proof
Definitions occuring in Statement : 
geo-lt: p < q, 
geo-add-length: p + q, 
geo-X: X, 
geo-O: O, 
euclidean-plane: EuclideanPlane, 
geo-between: a_b_c, 
geo-point: Point, 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
set: {x:A| B[x]} 
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
member: t ∈ T, 
basic-geometry: BasicGeometry, 
uall: ∀[x:A]. B[x], 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
rev_implies: P ⇐ Q, 
or: P ∨ Q, 
subtype_rel: A ⊆r B, 
prop: ℙ, 
euclidean-plane: EuclideanPlane, 
guard: {T}, 
uimplies: b supposing a, 
squash: ↓T, 
true: True, 
false: False
Lemmas referenced : 
geo-sep-iff-or-lt, 
geo-add-length_wf1, 
geo-lt_wf, 
geo-add-length_wf, 
subtype-geo-length-type, 
geo-sep-or, 
geo-between_wf, 
geo-O_wf, 
geo-X_wf, 
geo-sep_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-point_wf, 
geo-add-length-cancel-left-lt, 
geo-lt-add1_2, 
geo-add-length-lt-sep, 
geo-length-equality, 
squash_wf, 
true_wf, 
geo-length-type_wf, 
basic-geometry_wf, 
geo-lt-sep, 
geo-lt_transitivity, 
geo-le_weakening-lt, 
geo-lt-irrefl2, 
geo-add-length-cancel-right-lt, 
geo-add-length-comm, 
subtype_rel_self, 
iff_weakening_equal
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
sqequalRule, 
hypothesisEquality, 
isectElimination, 
hypothesis, 
productElimination, 
independent_functionElimination, 
inlFormation_alt, 
universeIsType, 
applyEquality, 
because_Cache, 
setElimination, 
rename, 
lambdaEquality_alt, 
dependent_set_memberEquality_alt, 
instantiate, 
independent_isectElimination, 
unionElimination, 
inhabitedIsType, 
setIsType, 
equalityTransitivity, 
equalitySymmetry, 
hyp_replacement, 
imageElimination, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
voidElimination, 
universeEquality
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b:\{a:Point|  O\_X\_a\}  .    (a  +  a  <  b  +  b  {}\mRightarrow{}  a  <  b)
Date html generated:
2019_10_16-PM-01_38_58
Last ObjectModification:
2019_03_20-PM-02_52_09
Theory : euclidean!plane!geometry
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