antiderivatives don't work, SKIP

> restart;
assume(a>0);
additionally(a<1);

> u:=t->piecewise(t<a,1,-1);
x1:=t->int(u(s),s=0..t);
x2:=t->int((x1(r))^2,r=0..t);

> plot([y1,y2,a=0..1],color=red,
view=[-1..1,-0.2..0.5]);

> a:='a';

>

> y1:=x1(1);
y2:=x2(1);

> with(plots):

> display([seq(
plot([x1,x2,0..1],color=red),
a=[seq(k/10,k=1..9)])]);