Nuprl Lemma : geo-add-length-cancel-left-lt3
∀e:BasicGeometry. ∀y,z:Length.  (z < 0 + y 
⇐⇒ z < y)
Proof
Definitions occuring in Statement : 
geo-lt: p < q
, 
geo-add-length: p + q
, 
geo-zero-length: 0
, 
geo-length-type: Length
, 
basic-geometry: BasicGeometry
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
rev_implies: P 
⇐ Q
, 
squash: ↓T
, 
true: True
, 
subtype_rel: A ⊆r B
, 
uimplies: b supposing a
, 
guard: {T}
, 
geo-zero-length: 0
, 
geo-lt: p < q
, 
exists: ∃x:A. B[x]
, 
cand: A c∧ B
, 
basic-geometry: BasicGeometry
, 
euclidean-plane: EuclideanPlane
, 
rev_uimplies: rev_uimplies(P;Q)
, 
geo_ge: geo_ge(e; p; q)
Lemmas referenced : 
geo-lt_wf, 
geo-add-length_wf, 
geo-zero-length_wf, 
geo-length-type_wf, 
basic-geometry_wf, 
geo-add-length-cancel-left-lt, 
equal_wf, 
geo-add-length-comm, 
iff_weakening_equal, 
geo-add-length-zero, 
squash_wf, 
true_wf, 
geo-sep_wf, 
geo-le_wf, 
geo-length_wf, 
geo-mk-seg_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
basic-geometry-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-le-add1, 
geo-le_functionality_wrt_implies, 
geo-le_weakening, 
geo-add-length_functionality_wrt_le
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
independent_pairFormation, 
universeIsType, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
inhabitedIsType, 
independent_functionElimination, 
applyEquality, 
lambdaEquality_alt, 
imageElimination, 
because_Cache, 
natural_numberEquality, 
sqequalRule, 
imageMemberEquality, 
baseClosed, 
equalityTransitivity, 
equalitySymmetry, 
independent_isectElimination, 
productElimination, 
dependent_pairFormation_alt, 
promote_hyp, 
productIsType, 
setElimination, 
rename, 
instantiate, 
dependent_functionElimination
Latex:
\mforall{}e:BasicGeometry.  \mforall{}y,z:Length.    (z  <  0  +  y  \mLeftarrow{}{}\mRightarrow{}  z  <  y)
Date html generated:
2019_10_16-PM-01_20_17
Last ObjectModification:
2018_12_03-PM-09_22_21
Theory : euclidean!plane!geometry
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