Specialized Error-Signalling Forms and Macros

CLtL2 Reference 

variable *IGNORE-MUSTS?*
If non-NIL, all must forms are ignored

macro MUST : (form format-string &rest arguments)

variable *SUSPEND-TYPE-CHECKING?*
CHECK-TYPE tests are performed iff this is non-nil

macro CHECK-TYPE : (object pred)

Specialized Error-Signalling Forms and Macros Home General Error-Signalling Functions