ML antiquotation "instantiate"


  • ML antiquotation "instantiate" allows to instantiate formal entities (types, terms, theorems) with values given ML. This works uniformly for "typ", "term", "prop", "ctyp", "cterm", "cprop", "lemma" --- given as a keyword after the instantiation. A mode "(schematic)" behind the keyword means that some variables may remain uninstantiated (fixed in the specification and schematic in the result); by default, all variables need to be instantiated.

Examples in HOL:

fun make_assoc_type (A, B) =
  \<^instantiate>‹'a = A and 'b = B in typ ‹('a × 'b) list››;

val make_assoc_list =
  map (fn (x, y) =>
    \<^instantiate>‹'a = ‹fastype_of x› and 'b = ‹fastype_of y› and
      x and y in term ‹(x, y)› for x :: 'a and y :: 'b›);

fun symmetry x y =
  \<^instantiate>‹'a = ‹Thm.ctyp_of_cterm x› and x and y in
    lemma ‹x = y ⟹ y = x› for x y :: 'a by simp›

fun symmetry_schematic A =
  \<^instantiate>‹'a = A in
    lemma (schematic) ‹x = y ⟹ y = x› for x y :: 'a by simp›

This refers to Isabelle/54085e37ce4d. Some applications are in the preceeding changesets.

Written by makarius on Oct 28 2021, 9:50 PM.

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