old_contents: from lcapy import *
  
  alpha = symbol('alpha')
  t0 = symbol('t0')
  f0 = symbol('f0')
  w0 = 2 * pi * f0
  
  sigs = [texpr('x(t)'), texpr('x(a * t)'), texpr('x(t - tau)'),
          cos(w0 * t), sin(w0 * t), exp(j * w0 * t),
          texpr(1), t, t**2, delta(t), delta(t - t0),
          H(t), t * H(t), sign(t),
          exp(-abs(t)), exp(-t) * H(t)]
  
  for sig in sigs:
      print(':math:`%s \\longleftrightarrow %s`\n' % (sig.latex(), sig(s).latex()))
  
new_contents: from lcapy import *
  
  alpha = symbol('alpha')
  t0 = symbol('t0')
  f0 = symbol('f0')
  w0 = 2 * pi * f0
  
  sigs = [texpr('x(t)'), texpr('x(a * t)'), texpr('x(t - tau)'),
          cos(w0 * t), sin(w0 * t), exp(j * w0 * t),
          texpr(1), t, t**2, delta(t), delta(t - t0),
          H(t), t * H(t), sign(t),
          exp(-abs(t)), exp(-t) * H(t),
          rect(t - 0.5), tri(t - 1), ramp(t), rampstep(t)]
  
  for sig in sigs:
      print(':math:`%s \\longleftrightarrow %s`\n' % (sig.latex(), sig(s).latex()))
  
subject: Add some LT