So I now finally understand that no-tactics miz3 can be used as a 
theorem-prover, but that I was not doing so: miz3 and MESON won't try to prove 
anything except my statements 
   x by th1, th2, ...
and only by trying to build a FOL proof of the implication
th1 /\ th2 /\ th3 ... ==> x 
then as long as my statements `x by th1, th2, ...' seem obvious to me, I run 
only a very minor risk of miz3 doing something really smart that I don't 
understand.  That's great, and thanks to everyone for helping me understand 
this. 

I'm curious about using no-tactics miz3 or any other proof assistant to produce 
1-line proofs, though.   I'm not doing very well with miz3, and I suppose 
that's a good thing.  I set the timeout pretty high
timeout := 4000;;
and I timed out (on an old slow machine) at 18 & 26 million in trying to 
convert some pretty simple proofs to 1-line proofs (original proofs commented 
out): 

let Line01infinity_THM = thm `;     :: #2 timeout at 18,678,485
  let X be point;
  let l m be point_set;
  assume Line l /\ Line m     [H0];
  assume ~(l = m)     [H1];
  assume X IN l /\ X IN m     [H2];
  thus l INTER m = {X}

  :: proof
  ::   assume ~(l INTER m = {X})     [H3];
  ::   X IN l INTER m     by H2, IN_INTER;
  ::   consider A such that
  ::   A IN l INTER m  /\ ~(A = X)     [X1] by -, H3, BiggerThanSingleton_THM;
  ::   A IN l /\ X IN l /\ A IN m /\ X IN m     by H0, -, H2, IN_INTER;
  ::   l = m     by H0, -, X1, I1;
  ::   F     by -, H1;
  :: qed     by -
  by  H0, H1, H2, IN_INTER, BiggerThanSingleton_THM, I1`;;


let SameSideLinesIntersect1Point_THM = thm `;    :: #2 timeout at  26,338,897 
  let A B X be point;
  let l m be point_set;
  assume Line l /\ Line m                [H0];
  assume l INTER m = {X}                    [H1];
  assume A IN m DELETE X /\ B IN m DELETE X          [H2];
  assume ~(A,B same_side l)             [H3];
  thus  A NOTIN l /\ B NOTIN l /\ X IN open (A,B)

  :: proof
  ::   A NOTIN l /\ B NOTIN l     [notABl] by H1, H2, EquivIntersectionHelp_THM;
  ::   A IN m /\ B IN m /\ ~(A = X) /\ ~(B = X)     [H2'] by H2, IN_DELETE;
  ::   ~(open (A,B) INTER l = {})     [nonempty] by H0, H3, 
SameSideDisjointIntersection_THM;
  ::   open (A,B) SUBSET m     [ABm] by H0, H2', OpenIntervalSubsetLine_THM;
  ::   open (A,B) INTER l SUBSET {X} by -, SubsetTensor_THM, H1, INTER_COMM;
  ::   X IN open (A,B) INTER l by nonempty, -, NonemptySubsetSing_THM;
  :: qed     by notABl, -, IN_INTER
  by H0, H1, H2, H3, EquivIntersectionHelp_THM, IN_DELETE, 
SameSideDisjointIntersection_THM, OpenIntervalSubsetLine_THM, SubsetTensor_THM, 
INTER_COMM, NonemptySubsetSing_THM, IN_INTER`;;


I think everyone will agree that these two results look pretty obvious.   
Line01infinity_THM says that if a point X belongs to two lines distinct l and 
m, then l INTER m = {X}.  That's just axiom I1, two points determine a line.   
The next result says that if l INTER m = {X} and points A, B on m are on 
opposite sides of l, then X must be between A and B.   If MESON can't prove 
that in 26 million whatevers, then I think I agree with Ramana and Michael that 
MESON isn't the top FOL prover.  I bet I could do a lot better if I learned how 
to use HOL tactics.  I'm interested in seeing if some better FOL prover would 
verify such 1-line proof versions of most of my result.  

Josef, let me try again.  I apologize for not knowing the terminology or 
anything about Vampire.  Would there be a way to turn my 971 lines of Tarski 
code http://www.math.northwestern.edu/~richter/TarskiAxiomGeometryCurry.ml 
(which for Freek I made all my predicates official curried HOL functions, in 
order to show that holby is weaker than Mizar) into  say 150 lines of 1-line 
proofs that a top FOL prover would then verify?  I think you did something 
like, but don't have the 150 line file.

-- 
Best,
Bill 

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