Control based on absolute expression (assembly performed when the value is true).
| If this control instruction and the corresponding ELSEIF, ELSEIFN, or ELSE control instruction exist, assembles the block enclosed within this control instruction and the corresponding control instruction. | 
| If none of the corresponding control instruction detailed above exist, assembles the block enclosed within this control instruction and the corresponding ENDIF control instruction. | 
Skips to the ELSEIF, ELSEIFN, ELSE, or ENDIF control instruction corresponding to this control instruction.
| With these conditional assembly control instructions, source statements subject to assembly can be changed without major modifications to the source program. |