Nuprl Lemma : cong3-in-half-plane
∀e:EuclideanPlane. ∀a,b,c,x,y,u:Point.
  (c # ab ⇒ u # xy ⇒ ab ≅ xy ⇒ (∃z:Point. (Cong3(abc,xyz) ∧ z # xy ∧ (u leftof xy ⇐⇒ z leftof xy))))
Proof
Definitions occuring in Statement : 
geo-cong-tri: Cong3(abc,a'b'c'), 
euclidean-plane: EuclideanPlane, 
geo-congruent: ab ≅ cd, 
geo-lsep: a # bc, 
geo-left: a leftof bc, 
geo-point: Point, 
all: ∀x:A. B[x], 
exists: ∃x:A. B[x], 
iff: P ⇐⇒ Q, 
implies: P ⇒ Q, 
and: P ∧ Q
Definitions unfolded in proof : 
geo-lsep: a # bc, 
geo-eq: a ≡ b, 
stable: Stable{P}, 
uiff: uiff(P;Q), 
geo-perp-in: ab  ⊥x cd, 
euclidean-plane: EuclideanPlane, 
geo-cong-tri: Cong3(abc,a'b'c'), 
cand: A c∧ B, 
oriented-plane: OrientedPlane, 
squash: ↓T, 
sq_stable: SqStable(P), 
basic-geometry: BasicGeometry, 
sq_exists: ∃x:A [B[x]], 
subtract: n - m, 
cons: [a / b], 
select: L[n], 
false: False, 
exists: ∃x:A. B[x], 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
not: ¬A, 
uimplies: b supposing a, 
or: P ∨ Q, 
decidable: Dec(P), 
lelt: i ≤ j < k, 
rev_implies: P ⇐ Q, 
int_seg: {i..j-}, 
top: Top, 
l_all: (∀x∈L.P[x]), 
geo-colinear-set: geo-colinear-set(e; L), 
iff: P ⇐⇒ Q, 
prop: ℙ, 
subtype_rel: A ⊆r B, 
uall: ∀[x:A]. B[x], 
and: P ∧ Q, 
guard: {T}, 
member: t ∈ T, 
implies: P ⇒ Q, 
all: ∀x:A. B[x]
Lemmas referenced : 
not-left-and-right, 
geo-cong-tri_wf, 
lsep-all-sym, 
colinear-lsep-cycle, 
geo-sep-or, 
geo-between-symmetry, 
lsep-opposite-iff, 
geo-between_wf, 
geo-between_functionality, 
geo-length-flip, 
geo-left_functionality, 
geo-congruence-identity, 
minimal-not-not-excluded-middle, 
geo-lsep_functionality, 
geo-colinear_functionality, 
geo-perp-in_functionality, 
geo-eq_weakening, 
geo-congruent_functionality, 
minimal-double-negation-hyp-elim, 
geo-congruent-iff-length, 
geo-congruent-sep, 
geo-congruent-symmetry, 
geo-between-implies-colinear, 
geo-colinear-same, 
right-angle-SAS, 
not_wf, 
false_wf, 
stable__geo-congruent, 
geo-sep-sym, 
geo-extend-exists, 
lsep-all-sym2, 
left-right-sep, 
sq_stable__geo-left, 
sq_stable__geo-perp-in, 
sq_stable__and, 
geo-left_wf, 
geo-perp-in_wf, 
Euclid-erect-2perp, 
colinear-cong3, 
geo-point_wf, 
geo-lsep_wf, 
geo-primitives_wf, 
euclidean-plane-structure_wf, 
euclidean-plane_wf, 
subtype_rel_transitivity, 
euclidean-plane-subtype, 
euclidean-plane-structure-subtype, 
geo-congruent_wf, 
geo-colinear_wf, 
istype-less_than, 
istype-le, 
int_formula_prop_less_lemma, 
intformless_wf, 
decidable__lt, 
int_formula_prop_wf, 
int_term_value_constant_lemma, 
int_formula_prop_le_lemma, 
int_formula_prop_not_lemma, 
istype-int, 
itermConstant_wf, 
intformle_wf, 
intformnot_wf, 
full-omega-unsat, 
decidable__le, 
length_of_nil_lemma, 
istype-void, 
length_of_cons_lemma, 
geo-colinear-is-colinear-set, 
lsep-iff-all-sep, 
geo-sep_wf, 
lsep-implies-sep, 
Euclid-drop-perp-1
Rules used in proof : 
equalityTransitivity, 
promote_hyp, 
unionIsType, 
equalitySymmetry, 
functionEquality, 
unionEquality, 
imageElimination, 
baseClosed, 
imageMemberEquality, 
productEquality, 
setElimination, 
rename, 
instantiate, 
functionIsType, 
inhabitedIsType, 
productIsType, 
lambdaEquality_alt, 
dependent_pairFormation_alt, 
approximateComputation, 
independent_isectElimination, 
unionElimination, 
independent_pairFormation, 
natural_numberEquality, 
voidElimination, 
isect_memberEquality_alt, 
sqequalRule, 
applyEquality, 
isectElimination, 
universeIsType, 
dependent_set_memberEquality_alt, 
productElimination, 
hypothesis, 
independent_functionElimination, 
because_Cache, 
hypothesisEquality, 
thin, 
dependent_functionElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
cut, 
lambdaFormation_alt, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c,x,y,u:Point.
    (c  \#  ab
    {}\mRightarrow{}  u  \#  xy
    {}\mRightarrow{}  ab  \mcong{}  xy
    {}\mRightarrow{}  (\mexists{}z:Point.  (Cong3(abc,xyz)  \mwedge{}  z  \#  xy  \mwedge{}  (u  leftof  xy  \mLeftarrow{}{}\mRightarrow{}  z  leftof  xy))))
Date html generated:
2019_10_29-AM-09_18_22
Last ObjectModification:
2019_10_18-PM-03_15_17
Theory : euclidean!plane!geometry
Home
Index