Nuprl Lemma : geo-add-length-cancel-left-le
∀[e:BasicGeometry]. ∀[x,y,z:Length].  x ≤ y supposing z + x ≤ z + y
Proof
Definitions occuring in Statement : 
geo-add-length: p + q
, 
geo-le: p ≤ q
, 
geo-length-type: Length
, 
basic-geometry: BasicGeometry
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
Definitions unfolded in proof : 
squash: ↓T
, 
geo-le: p ≤ q
, 
guard: {T}
, 
implies: P 
⇒ Q
, 
so_apply: x[s]
, 
basic-geometry: BasicGeometry
, 
all: ∀x:A. B[x]
, 
so_lambda: λ2x.t[x]
, 
subtype_rel: A ⊆r B
, 
and: P ∧ Q
, 
quotient: x,y:A//B[x; y]
, 
prop: ℙ
, 
geo-length-type: Length
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
exists: ∃x:A. B[x]
, 
geo-add-length: p + q
, 
iff: P 
⇐⇒ Q
, 
cand: A c∧ B
, 
false: False
, 
not: ¬A
, 
stable: Stable{P}
, 
true: True
, 
uiff: uiff(P;Q)
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
geo-length-type_wf, 
Error :basic-geo-primitives_wf, 
Error :basic-geo-structure_wf, 
basic-geometry_wf, 
subtype_rel_transitivity, 
basic-geometry-subtype, 
geo-eq_wf, 
equal-wf-base, 
equal_wf, 
geo-add-length_wf, 
geo-X_wf, 
geo-O_wf, 
geo-between_wf, 
geo-point_wf, 
set_wf, 
subtype-geo-length-type, 
geo-le_wf, 
geo-between-exchange4, 
geo-between-exchange3, 
geo-between-inner-trans, 
geo-between-symmetry, 
geo-congruent_wf, 
geo-sep_wf, 
geo-Op-sep, 
geo-extend-property, 
geo-eq_weakening, 
geo-between_functionality, 
geo-add-length_wf1, 
member_wf, 
exists_wf, 
and_wf, 
geo-sep-O-X, 
geo-between-same-side2, 
not_wf, 
stable__geo-between, 
geo-add-length-is-zero, 
geo-add-length-implies-eq-zero, 
iff_weakening_equal, 
geo-add-length-assoc, 
true_wf, 
squash_wf, 
geo-congruent-iff-length, 
geo-add-length-between, 
geo-mk-seg_wf, 
geo-length_wf, 
geo-length-flip, 
geo-zero-length-iff, 
geo-between-trivial
Rules used in proof : 
isect_memberEquality, 
baseClosed, 
imageMemberEquality, 
imageElimination, 
independent_isectElimination, 
instantiate, 
productEquality, 
independent_functionElimination, 
lambdaFormation, 
rename, 
setElimination, 
dependent_functionElimination, 
lambdaEquality, 
because_Cache, 
equalitySymmetry, 
equalityTransitivity, 
applyEquality, 
productElimination, 
pertypeElimination, 
hypothesis, 
sqequalRule, 
hypothesisEquality, 
thin, 
isectElimination, 
extract_by_obid, 
pointwiseFunctionalityForEquality, 
sqequalHypSubstitution, 
cut, 
introduction, 
isect_memberFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
dependent_set_memberEquality, 
setEquality, 
dependent_pairFormation, 
independent_pairFormation, 
voidElimination, 
universeEquality, 
natural_numberEquality, 
applyLambdaEquality
Latex:
\mforall{}[e:BasicGeometry].  \mforall{}[x,y,z:Length].    x  \mleq{}  y  supposing  z  +  x  \mleq{}  z  +  y
Date html generated:
2017_10_02-PM-06_18_28
Last ObjectModification:
2017_08_05-PM-04_13_08
Theory : euclidean!plane!geometry
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