Nuprl Lemma : right-angle-sum
∀g:EuclideanPlane. ∀a,b,c,x,y,z,i,j,k:Point.
  (a ≠ b ⇒ b ≠ c ⇒ x ≠ y ⇒ y ≠ z ⇒ Rabc ⇒ Rxyz ⇒ i-j-k ⇒ abc + xyz ≅ ijk)
Proof
Definitions occuring in Statement : 
hp-angle-sum: abc + xyz ≅ def, 
euclidean-plane: EuclideanPlane, 
right-angle: Rabc, 
geo-strict-between: a-b-c, 
geo-sep: a ≠ b, 
geo-point: Point, 
all: ∀x:A. B[x], 
implies: P ⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
member: t ∈ T, 
basic-geometry-: BasicGeometry-, 
uall: ∀[x:A]. B[x], 
subtype_rel: A ⊆r B, 
prop: ℙ, 
basic-geometry: BasicGeometry, 
uimplies: b supposing a, 
geo-colinear-set: geo-colinear-set(e; L), 
l_all: (∀x∈L.P[x]), 
top: Top, 
int_seg: {i..j-}, 
lelt: i ≤ j < k, 
and: P ∧ Q, 
decidable: Dec(P), 
or: P ∨ Q, 
not: ¬A, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
exists: ∃x:A. B[x], 
false: False, 
select: L[n], 
cons: [a / b], 
subtract: n - m, 
sq_exists: ∃x:A [B[x]], 
euclidean-plane: EuclideanPlane, 
sq_stable: SqStable(P), 
squash: ↓T, 
iff: P ⇐⇒ Q, 
hp-angle-sum: abc + xyz ≅ def, 
cand: A c∧ B, 
geo-perp-in: ab  ⊥x cd, 
guard: {T}
Lemmas referenced : 
Euclid-erect-perp, 
geo-strict-between-sep1, 
geo-sep_wf, 
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, 
geo-colinear_wf, 
sq_stable__and, 
geo-perp-in_wf, 
geo-lsep_wf, 
sq_stable__geo-perp-in, 
sq_stable__geo-lsep, 
lsep-iff-all-sep, 
geo-sep-sym, 
geo-right-angles-congruent, 
geo-colinear-same, 
geo-strict-between-sep2, 
geo-strict-between-sep3, 
geo-between-trivial2, 
geo-out_weakening, 
geo-eq_weakening, 
geo-cong-angle_wf, 
geo-between_wf, 
geo-out_wf, 
geo-strict-between_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
right-angle_wf, 
geo-point_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
sqequalRule, 
because_Cache, 
independent_functionElimination, 
hypothesis, 
dependent_set_memberEquality_alt, 
universeIsType, 
isectElimination, 
applyEquality, 
independent_isectElimination, 
isect_memberEquality_alt, 
voidElimination, 
natural_numberEquality, 
independent_pairFormation, 
unionElimination, 
approximateComputation, 
dependent_pairFormation_alt, 
lambdaEquality_alt, 
productIsType, 
setElimination, 
rename, 
productElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
inhabitedIsType, 
instantiate
Latex:
\mforall{}g:EuclideanPlane.  \mforall{}a,b,c,x,y,z,i,j,k:Point.
    (a  \mneq{}  b  {}\mRightarrow{}  b  \mneq{}  c  {}\mRightarrow{}  x  \mneq{}  y  {}\mRightarrow{}  y  \mneq{}  z  {}\mRightarrow{}  Rabc  {}\mRightarrow{}  Rxyz  {}\mRightarrow{}  i-j-k  {}\mRightarrow{}  abc  +  xyz  \mcong{}  ijk)
Date html generated:
2019_10_16-PM-02_05_35
Last ObjectModification:
2019_06_05-AM-09_36_44
Theory : euclidean!plane!geometry
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