A Boolean flag is cell-sized. A cell with all bits clear represents the
flag false
and a flag with all bits set represents the flag
true
. Words that check a flag (for example, IF
) will treat
a cell that has any bit set as true
.
Constant
– f is a cell with all bits set.
Constant
– f is a cell with all bits clear.
Set the (value of the) variable at a-addr to true
.
Set the (value of the) variable at a-addr to false
.
If f is false, u is u2, otherwise u1.