Nuprl Lemma : hp-angle-sum-lt3
∀e:EuclideanPlane. ∀a,b,c,x,y,z,i,j,k,a',b',c',x',y',z',i',j',k':Point.
  (a' # b'c'
  
⇒ abc + xyz ≅ ijk
  
⇒ a'b'c' + x'y'z' ≅ i'j'k'
  
⇒ ijk ≅a i'j'k'
  
⇒ a # bc
  
⇒ x # yz
  
⇒ i # jk
  
⇒ abc < a'b'c'
  
⇒ x'y'z' < xyz)
Proof
Definitions occuring in Statement : 
hp-angle-sum: abc + xyz ≅ def
, 
geo-lt-angle: abc < xyz
, 
geo-cong-angle: abc ≅a xyz
, 
euclidean-plane: EuclideanPlane
, 
geo-lsep: a # bc
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
Definitions unfolded in proof : 
basic-geometry: BasicGeometry
, 
uimplies: b supposing a
, 
guard: {T}
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
member: t ∈ T
, 
and: P ∧ Q
, 
exists: ∃x:A. B[x]
, 
hp-angle-sum: abc + xyz ≅ def
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
geo-lt-angle: abc < xyz
, 
geo-out: out(p ab)
, 
basic-geometry-: BasicGeometry-
, 
cand: A c∧ B
, 
geo-colinear-set: geo-colinear-set(e; L)
, 
l_all: (∀x∈L.P[x])
, 
top: Top
, 
int_seg: {i..j-}
, 
lelt: i ≤ j < k
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
not: ¬A
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
false: False
, 
select: L[n]
, 
cons: [a / b]
, 
subtract: n - m
, 
geo-cong-angle: abc ≅a xyz
, 
uiff: uiff(P;Q)
, 
geo-tri: Triangle(a;b;c)
, 
squash: ↓T
, 
true: True
, 
geo-strict-between: a-b-c
, 
geo-lsep: a # bc
, 
oriented-plane: OrientedPlane
, 
l_member: (x ∈ l)
, 
nat: ℕ
, 
le: A ≤ B
, 
less_than': less_than'(a;b)
, 
less_than: a < b
, 
ge: i ≥ j 
, 
append: as @ bs
, 
so_lambda: so_lambda(x,y,z.t[x; y; z])
, 
so_apply: x[s1;s2;s3]
Lemmas referenced : 
geo-point_wf, 
hp-angle-sum_wf, 
geo-cong-angle_wf, 
geo-primitives_wf, 
euclidean-plane-structure_wf, 
euclidean-plane_wf, 
subtype_rel_transitivity, 
euclidean-plane-subtype, 
euclidean-plane-structure-subtype, 
geo-lsep_wf, 
geo-lt-angle_wf, 
geo-cong-angle-preserves-lt-angle2, 
geo-cong-angle-symm2, 
cong-angle-preserves-lsep_strong, 
geo-proper-extend-exists, 
geo-sep-sym, 
geo-strict-between-sep3, 
geo-out-if-between, 
geo-strict-between-sym, 
out-preserves-lsep, 
lsep-symmetry, 
lsep-all-sym, 
colinear-lsep-cycle, 
geo-strict-between-sep2, 
geo-colinear-is-colinear-set, 
geo-strict-between-implies-colinear, 
length_of_cons_lemma, 
istype-void, 
length_of_nil_lemma, 
decidable__le, 
full-omega-unsat, 
intformnot_wf, 
intformle_wf, 
itermConstant_wf, 
istype-int, 
int_formula_prop_not_lemma, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_wf, 
decidable__lt, 
intformless_wf, 
int_formula_prop_less_lemma, 
istype-le, 
istype-less_than, 
lsep-implies-sep, 
geo-out_inversion, 
euclidean-plane-axioms, 
geo-sas, 
geo-congruent-iff-length, 
geo-cong-angle-transitivity, 
geo-between-sep, 
out-preserves-angle-cong_1, 
geo-between_wf, 
geo-strict-between-sep1, 
geo-five-segment, 
geo-between-symmetry, 
geo-strict-between-implies-between, 
geo-length-flip, 
geo-between-trivial, 
geo-add-length-between, 
geo-add-length_wf, 
squash_wf, 
true_wf, 
geo-length-type_wf, 
basic-geometry_wf, 
geo-congruent_wf, 
geo-out_weakening, 
geo-eq_weakening, 
geo-out_transitivity, 
geo-between-implies-colinear, 
geo-between-out, 
left-symmetry, 
geo-left-out-4, 
between-preserves-left-2, 
between-preserves-left-1, 
geo-left_wf, 
between-preserves-left-4, 
between-preserves-left-3, 
unique-angles-in-half-plane-better2, 
geo-cong-angle-symmetry, 
geo-cong-angle-symm3, 
unique-angles-in-half-plane-better, 
geo-out-interior-point-exists, 
geo-out-colinear, 
not-out-if-lsep, 
lsep-not-between, 
geo-out_wf, 
geo-sep_wf, 
out-cong-angle, 
lt-angle-implies-between-if-out, 
geo-colinear-append, 
cons_wf, 
nil_wf, 
length_wf, 
select_wf, 
nat_properties, 
intformand_wf, 
itermVar_wf, 
int_formula_prop_and_lemma, 
int_term_value_var_lemma, 
l_member_wf, 
list_ind_cons_lemma, 
list_ind_nil_lemma, 
geo-between-lt-angle, 
geo-strict-between-trans, 
geo-cong-angle-preserves-lt-angle, 
cong-tri-implies-cong-angle2
Rules used in proof : 
inhabitedIsType, 
because_Cache, 
sqequalRule, 
independent_isectElimination, 
instantiate, 
applyEquality, 
isectElimination, 
hypothesis, 
hypothesisEquality, 
dependent_functionElimination, 
extract_by_obid, 
introduction, 
universeIsType, 
cut, 
thin, 
productElimination, 
sqequalHypSubstitution, 
lambdaFormation_alt, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
independent_functionElimination, 
rename, 
isect_memberEquality_alt, 
voidElimination, 
dependent_set_memberEquality_alt, 
natural_numberEquality, 
independent_pairFormation, 
unionElimination, 
approximateComputation, 
dependent_pairFormation_alt, 
lambdaEquality_alt, 
productIsType, 
equalitySymmetry, 
functionIsType, 
equalityTransitivity, 
imageElimination, 
imageMemberEquality, 
baseClosed, 
setElimination, 
equalityIstype, 
int_eqEquality
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c,x,y,z,i,j,k,a',b',c',x',y',z',i',j',k':Point.
    (a'  \#  b'c'
    {}\mRightarrow{}  abc  +  xyz  \mcong{}  ijk
    {}\mRightarrow{}  a'b'c'  +  x'y'z'  \mcong{}  i'j'k'
    {}\mRightarrow{}  ijk  \mcong{}\msuba{}  i'j'k'
    {}\mRightarrow{}  a  \#  bc
    {}\mRightarrow{}  x  \#  yz
    {}\mRightarrow{}  i  \#  jk
    {}\mRightarrow{}  abc  <  a'b'c'
    {}\mRightarrow{}  x'y'z'  <  xyz)
Date html generated:
2019_10_16-PM-02_24_22
Last ObjectModification:
2019_10_02-AM-10_31_31
Theory : euclidean!plane!geometry
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