- STRUCTURE
- SYNOPSIS
- Passes a theorem unchanged to a theorem-tactic. 
- DESCRIPTION
- For any theorem-tactic ttac and theorem th, the application
ALL_THEN ttac th results simply in ttac th, that is, the theorem
is passed unchanged to the theorem-tactic. ALL_THEN is the identity
theorem-tactical. 
- FAILURE
- The application of ALL_THEN to a theorem-tactic never fails. The resulting
theorem-tactic fails under exactly the same conditions as the original one. 
- USES
- Writing compound tactics or tacticals, e.g. terminating list iterations
of theorem-tacticals. 
- SEEALSO