Direct algebraic logic (D.A.L.) is a method for entering equations on scientific calculators which allows symbols and numbers to be entered as they are written. SHARP introduced it in 1992. Today DAL is used almost with every scientific calculator except very simple calculators and those which use Reverse Polish Notation.
Example:
- with reverse polish notation
3
0
SIN
3
0
COS
×
- with algebraic logic
3
0
SIN
×
3
0
COS
=
- with direct algebraic logic
SIN
3
0
→
×
COS
3
0
ENTER
Note the →
: most DAL calculators will automatically insert needed (
)
and the →
skips over the )
from the sin operation. Of Equipped with an alphanumeric display the calculator will display SIN(30)×COS(30) before pressing ENTER
.
Criticism
As seen in the example above the increased need for (
and )
results into larger amount of key presses to enter a formula. In the example above: D.A.L. 9 key presses, A.L.: 8 key presses, RPN: 7 key presses.