∫ 1/sqrt(x) from 0 to 1 : OPEN4
              Q = 1.99952
          exact = 2
          calls = 400
estimated error = 0.00299952
   actual error = 0.000483882

∫ 1/sqrt(x) from 0 to 1 : CLENSHAW_CURTIS
              Q = 1.99987
          exact = 2
          calls = 8
estimated error = 0.00299987
   actual error = 0.000129682

∫ log(x)/sqrt(x) from 0 to 1 : OPEN4
              Q = -3.99926
          exact = -4
          calls = 424
estimated error = 0.00499926
   actual error = 0.000739677

∫ log(x)/sqrt(x) from 0 to 1 : CLENSHAW_CURTIS
              Q = -3.99486
          exact = -4
          calls = 36
estimated error = 0.00499486
   actual error = 0.00514201

∫ 4*sqrt(1-x*x)/M_PI from 0 to 1 : OPEN4
              Q =    1.00000000000188915550
          exact =    1.00000000000000000000
          calls = 3924
estimated error = 2e-09
   actual error = 1.88916e-12

∫ 4*sqrt(1-x*x)/M_PI from 0 to 1 : CLENSHAW_CURTIS
              Q =    0.99999999999998023803
          exact =    1.00000000000000000000
          calls = 3756
estimated error = 2e-09
   actual error = 1.9762e-14