Does anyone know how to formalize an axiom schema in HOL Light?  I'm interested 
in formalizing the Tarski axiomatic geometry 
Axiom schema of Continuity
http://en.wikipedia.org/wiki/Tarski%27s_axioms#The_axioms
and the part I don't know how to handle involves the universal quantification

Let φ(x) and ψ(y) be first-order formulae containing no free instances of 
either a or b

The Tarski first order language is quite simple, and is explained below in a 
code fragment of 
hol_light/RichterHilbertAxiomGeometry/TarskiAxiomGeometry_read.ml
which John essentially wrote for me years ago.  But if someone had formalized 
an axiom schema for a different first order language that's surely good enough 
for me.  Michael Beeson tells me that this is not necessary, as we can instead 
just adopt every axiom-instance of the axiom schema that we actually use.  Do 
folks have an opinion on that?

I'd like to install HOL Light on a Mac that's not connected to the net, and I'm 
intimidated by OPAM:
http://caml.inria.fr/ocaml/release.en.html#idp1286576
Is there an earlier version of OCaml/Camlp for which inria distribute MacOS 
binaries that folks trust for building HOL Light?

-- 
Best,
Bill 

NewConstant("≃",`:TarskiPlane#TarskiPlane->TarskiPlane#TarskiPlane->bool`);;
NewConstant("ℬ", `:TarskiPlane->TarskiPlane->TarskiPlane->bool`);;

ParseAsInfix("≃",(12, "right"));;

let A1 = NewAxiom `;
  ∀a b. a,b ≃ b,a`;;

let A2 = NewAxiom `;
  ∀a b p q r s. a,b ≃ p,q ∧ a,b ≃ r,s ⇒ p,q ≃ r,s`;;

let A3 = NewAxiom `;
  ∀a b c. a,b ≃ c,c ⇒ a = b`;;

let A4 = NewAxiom `;
  ∀a q b c. ∃x. ℬ q a x ∧ a,x ≃ b,c`;;

let A5 = NewAxiom `;
  ∀a b c x a' b' c' x'.
        ¬(a = b) ∧ a,b,c ≊ a',b',c' ∧
        ℬ a b x ∧ ℬ a' b' x' ∧ b,x ≃ b',x'
        ⇒ c,x ≃ c',x'`;;

let A6 = NewAxiom `;
  ∀a b. ℬ a b a ⇒ a = b`;;

let A7 = NewAxiom `;
  ∀a b p q z.  ℬ a p z ∧ ℬ b q z
    ⇒ ∃x. ℬ p x b ∧ ℬ q x a`;;

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