Sure.
Consider the Presentation assignment and suppose it was submitted and graded 75. Then:
round((||Presentation||/100)+0.49,0)=
round((75/100)+0.49,0)=
round(0.75+0.49,0)=
round(1.24,0)=
1
If the Presentation was not submitted:
round((||Presentation||/100)+0.49,0)=
round((0/100)+0.49,0)=
round(0+0.49,0)=
round(0.49,0)=
0
When the grade of a submitted Presentation is at least 1 point (out of 100) then
||Presentation|| is between 1 and 100,
||Presentation||/100 is between 0.01 and 1, and
||Presentation||/100+0.49 is between 0.5 and 1.49.
When the
round function is set to
0 decimals it rounds a number to the nearest integer, such that if the fraction is
>=0.5 it returns the
ceiling, and if the fraction is
<0.5 it returns the
floor. So,
round(n,0) applied to a number between 0.5 and 1.49 should return
1.
Set this way this part of the formula should return 1 for a graded Presentation and 0 for non-submission (or non-graded, or graded less than 1 point). And you have a flag.
If you have several assignments you can set a flag for each. The product of all flags is 0 if at least one is 0 and 1 only if all are 1. And so you have an "overall" flag which you can apply to the course grade.
Hope this makes it clearer.