Research Article

Formalization of Linear Space Theory in the Higher-Order Logic Proving System

Box 1

val s = “s: num_field”;
val membership = “0c IN s 1c IN s
       !a:complex b:complex. if a IN s b IN s
       then (a + b IN s) (a − b IN s) (a * b IN s) (if a < > 0 then b/a IN s else a = 0c)
       else F”;