Help with Piecewise function

[Snorre]

Hello Salvo,

yes you're right: the final 0 (the default case) matters, if you want your function to be defined everywhere.
Additionally: as the warning told you, a case t=0 (a single point) isn't very meaningful to integration (just think about it a bit). Nevertheless the Prime does it and it's up to you to be always a bit sceptical about machine-generated results. ;-)