| Ci(x)
| Cosine integral function
| See [https://en.wikipedia.org/wiki/Trigonometric_integral: | Trigonometric Integral on Wikipedia.]
|-
| Si(x)
| Sine integral function
| See [https://en.wikipedia.org/wiki/Trigonometric_integral: | Trigonometric Integral on Wikipedia.]
|-
| C(x)
| Cosine Fresnel integral function
| See [https://en.wikipedia.org/wiki/Fresnel_integral: | Fresnel Integral on Wikipedia.]
|-
| S(x)