Question: Plot of a certain curve

I have the following code of a plot:

plot(
[
add(BS(bb[4], t, i, 3)*bb[1](i+1), i = 0..n),
add(BS(bb[4], t, i, 3)*bb[2](i+1), i = 0..n),
t = 0..1
],
color=red, axes=normal, scaling=constrained, numpoints=100, thickness=2
):

and I get the following error:

Error, (in BS) cannot determine if this expression is true or false: 0 <= t and t < .54901960784313725490196078431373

The problem is that, in the definition of BS, there are some conditions that depend on the variable t. It seems that Maple does not use a specific value of t when executing BS. My solution is to plot specific points, i.e., 

plot(
[
seq([add(BS(bb[4], h/5000, i, 3)*bb[1](i+1), i = 0..n),
add(BS(bb[4], h/5000, i, 3)*bb[2](i+1), i = 0..n)], h=0..5000)
],
color=red, axes=normal, scaling=constrained, numpoints=100, thickness=2
):

Can this be done in a more elegant way?