Parse.remove_type

STRUCTURE

SYNOPSIS

Remove a type abbreviation from the type grammar.

DESCRIPTION

A call to remove_type_abbrev s removes any type abbreviations keyed on string s. As with other functions affecting the global grammar, there is a companion function, temp_remove_type_abbrev, which affects the grammar but does not cause the effect to be replayed in descendant theories.

If the string s is not a qualified name (of the form "thy$name"), then all type abbreviations with base name s are removed. If s does have a qualified name, then only a type abbreviation of that name and theory will be removed (if such exists).

FAILURE

Fails if the given string is a malformed qualified identifier (e.g., foo$$). If the given name is syntactically valid, but there are no abbreviations keyed to the given name, a call to remove_type_abbrev will silently do nothing.

EXAMPLE

The standard theory context (where pred_set is loaded), includes an abbreviation mapping ``:'a set`` to ``:'a -> bool``. It doesn’t print the abbreviated form back to the user, because its printing has been disabled with disable_tyabbrev_printing.

   > ``:'a set``;
   val it = ``:'a -> bool`` : hol_type

   > remove_type_abbrev "set";
   val it = (): unit

   > ``:'a set``;
   Exception- HOL_ERR ...

SEEALSO

disable_tyabbrev_printing, type_abbrev