I've now formalized all the theorems in the first 6 sections of my Hilbert 
axiomatic geometry paper http://www.math.northwestern.edu/~richter/hilbert.pdf 
in 2800 lines of miz3 code 
http://www.math.northwestern.edu/~richter/RichterHOL-LightMiz3HilbertAxiomGeometry.tar.gz
  My last result was Moise and Venema's Plane Separation axiom:

Prop 4.13: The complement in the plane of a line l is a disjoint union
of two nonempty convex sets H1 and H2. If P ∈ H1 and Q ∈ H2 , then 
¬(open (P,Q) ∩ l = ∅).

It's easy mathematically but used a lot of HOL set theory.  I'm very
happy to have formalized it, and I'm including the defs & thms below.


Ramana, I think my definition of power is quite different from any of your 3 
definitions.  I thought my last post was clear, but maybe it wasn't.  Let me 
try again:  I want to say that miz3 (without tactics) is so lacking in power 
that a human can read such miz3 proofs.  I think if anyone read my code, they 
could understand quite as easily as my paper.  I want to say that in such a 
miz3 line 
alpha by X1, X2, ..., Xn;
which miz3 says is OK, that a human will easily be able to check that results 
X1,..., Xn actually prove alpha. Provided that the human understands alpha, 
X1,...,Xn, of course.  I think this lack of power can be explained precisely 
with some kind of an upper bound.  

Now I believe that MESON is much more powerful than that.  I think we can all 
be astounded by what MESON can prove for us.  But I don't believe that miz3 
(without tactics) uses the full power of MESON. 

-- 
Best,
Bill 

PlaneComplement_DEF : thm =
  |- ∀ P A α. complement α P ⇔ P ∉ α

CONVEX : thm =
  |- ∀α. Convex α ⇔
             (∀ A B. A ∈ α ∧ B ∈ α ⇒ open (A,B) ⊂ α)

HalfPlaneConvexNonempty_THM : thm =
  |- ∀l H A.
         Line l ∧ A ∉ l ∧ 
         (∀X. X ∈ H ⇔ X ∉ l ∧ X,A same_side l)
         ⇒ ¬(H = ∅)  ∧  H ⊂ complement l  ∧  Convex H

PlaneSeparation_THM : thm =
  |- ∀ l. Line l
         ⇒ (∃ H1 H2.
                  H1 ∩ H2 = ∅ ∧ ¬(H1 = ∅) ∧ ¬(H2 = ∅) ∧
                  Convex H1 ∧ Convex H2 ∧ complement l = H1 ∪ H2 ∧
                  (∀P Q. P ∈ H1 ∧ Q ∈ H2 ⇒ ¬(P,Q same_side l)))



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