First (Built-in Mathematica Symbol)

First[expr] gives the first element in expr.

Most (Built-in Mathematica Symbol)

Most[expr] gives expr with the last element removed.

Patterns Involving Alternatives (Mathematica Tutorial)

Specifying patterns that involve alternatives. This defines h to give p when its argument is either a or b. The first two cases give p.

ManhattanDistance (Built-in Mathematica Symbol)

ManhattanDistance[u, v] gives the Manhattan or "city block" distance between vectors u and v.

Use Logical Operators (Mathematica How To)

Mathematica supports logical operators not only for programming, but for mathematical operations as well.

Grouping and Combining Elements of Lists (Mathematica Tutorial)

Functions for grouping together elements of lists. Here is a list. This groups the elements of the list in pairs, throwing away the single element left at the end.

Lists as Sets (Mathematica Tutorial)

Mathematica usually keeps the elements of a list in exactly the order you originally entered them. If you want to treat a Mathematica list like a mathematical set, however, ...

Distribute (Built-in Mathematica Symbol)

Distribute[f[x_1, x_2, ...]] distributes f over Plus appearing in any of the x_i. Distribute[expr, g] distributes over g. Distribute[expr, g, f] performs the distribution ...

Insert > Horizontal Lines (Mathematica Menu Item)

Horizontal Lines opens a submenu to insert a line of the specified thickness above or below the selected cell.

ReplaceList (Built-in Mathematica Symbol)

ReplaceList[expr, rules] attempts to transform the entire expression expr by applying a rule or list of rules in all possible ways, and returns a list of the results ...