def generator():
"""
Produces a dirac-delta y=k*d(t-a)
and step y=k*u(t-a).
Asks for integrals for each around a.
"""
t = var("t")
y = var("y")
a = randrange(3,7)
b = a - randrange(1,4)
c = a + randrange(2,5)
d = dirac_delta
u = unit_step
k = randrange(2,6)
d_integrand = (k*d(t-a))
u_integrand = (k*u(t-a))
return {
"d_integrand": d_integrand,
"u_integrand": u_integrand,
"b": b,
"c": c,
"d_int_value": k,
"u_int_value": k*(c-a),
}