"functions" - key terms from Wikipedia

analytic functions
basis functions
bessel functions
cognitive functions
color matching functions
complex analytic functions
complex functions
continuous functions
correlation functions
cryptographic hash functions
density functions
elementary functions
executive functions
functions
functions	such
gaussian functions
generic functions
hash functions
hermite functions
holomorphic functions
hyperbolic functions
impulse functions
inline functions
integrable functions
inverse trigonometric functions
judicial functions
latent functions
library functions
measurable functions
member functions
parser functions
procedures and functions
public functions
radial basis functions
rational functions
real analytic functions
regular functions
related functions
schwartz functions
sha hash functions
shadow functions
sine and cosine functions
smooth functions
special functions
spherical bessel functions
spherical harmonic functions
string functions
trigonometric functions
virtual functions
wave functions