Library /sys$common/syshlp/dbg$help.hlb DEBUG, SHOW, AST, Example  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  DBG> SHOW AST
  ASTs are enabled
  DBG> DISABLE AST
  DBG> SHOW AST
  ASTs are disabled
  DBG>

      The SHOW AST command indicates whether the delivery of ASTs is
      enabled.