The call type(x, protected) checks to see if the expression x is a name of type protected. It returns true if x is a protected name, and false otherwise.

Protection is used to prevent names from being modified by the user. Most of the Maple systems names are protected by default.

Names can be protected with the function protect; and protection can be removed with unprotect.

The set of protected names in Maple can be computed with select(type, {unames(), anames(anything)}, protected).