GridLinesStyle is an option for 2D graphics functions that specifies how grid lines should be rendered.
GroupCentralizer[group, g] returns the centralizer of the element g in group.
Gudermannian[z] gives the Gudermannian function gd(z).
HammingDistance[u, v] gives the Hamming distance between strings or vectors u and v.
HarmonicMean[list] gives the harmonic mean of the values in list.
Haversine[z] gives the haversine function hav(z).
HeavisideLambda[x] represents the triangle distribution \[CapitalLambda](x) which is nonzero for |x| < 1.HeavisideLambda[x_1, x_2, ...] represents the multidimensional ...
HeavisidePi[x] represents the box distribution \[CapitalPi](x), equal to 1 for |x| < 1/2 and 0 for |x| > 1/2.HeavisidePi[x_1, x_2, ...] represents the multidimensional box ...
HigmanSimsGroupHS[] represents the sporadic simple Higman\[Dash]Sims group HS.
HoldAllComplete is an attribute which specifies that all arguments to a function are not to be modified or looked at in any way in the process of evaluation.