evalb() cmd

[compsystems]

approx(seq((sin(x)^2+cos(x)^2)=1, x, 0, 20)) => [1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,​1.0=1.0,1.0=1.0]

evalb(approx(seq((sin(x)^2+cos(x)^2)=1, x, 0, 20)) =>
[1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1]

I think it must return.
[true,true,true,true,true,true,true,true,true,true,true,true,true,true]

evalb([1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0,1.0=1.0] =>
[true,true,true,true,true,true,true,true,true,true,true,true,true,true]

autosimplify(0); evalb(approx(seq((sin(x)^2+cos(x)^2)=1, x, 0, 20))) =>
nop Why?

[compsystems]

evalb works on a list correctly

evalb([0,1,1,0,1,0,1,0,0,0,1,0,1,0])

[false,true,true,false,true,false,true,false,false,false,true,false,true,false]

but not when in this case

evalb(isPrime([1,2,3,4,5,6,7,8,9,10,11,12,13,14]))