| S18ACF | Modified Bessel function K0x |
| S18ADF | Modified Bessel function K1x |
| S18AEF | Modified Bessel function I0x |
| S18AFF | Modified Bessel function I1x |
| S18CCF | Scaled modified Bessel function exK0x |
| S18CDF | Scaled modified Bessel function exK1x |
| S18CEF | Scaled modified Bessel function e-xI0x |
| S18CFF | Scaled modified Bessel function e-xI1x |