// control.asm: WORD p_true_branch,'1BRANCH',fasm anchor:p_1branch[] === Word: 1BRANCH .... Data stack: ( v -- ) .... "1BRANCH" is a function word that implements execution conditional by means of optionally adding the subsequent branch offset, or not, to the point of execution. If the value, v, is non-zero then the branch offset is added, and otherwise execution continues with the cell following the branch offset in the definition.