cheb_test:
  Test cheb.

  X   cheb(exp)(x)  exp(x)

    0.0000    1.00000000    1.00000000
    0.5000    1.64872122    1.64872122
    1.0000    2.71828175    2.71828175
    1.5000    4.48168898    4.48168898
    2.0000    7.38905573    7.38905621
    2.5000   12.18249321   12.18249416
    3.0000   20.08551788   20.08553696
    3.5000   33.11524582   33.11545181
    4.0000   54.59655380   54.59814835
    4.5000   90.00759888   90.01712799
    5.0000  148.36595154  148.41316223

cheb_test:
  Normal end of execution.