Data type of function environments
DOM_FUNC_ENV is the data type of function environments.
MuPAD® uses function environments (domain type DOM_FUNC_ENV) to integrate functions into the system. All MuPAD library functions and most kernel functions are implemented as function environments.
A function environment stores special function attributes (slots) in an internal table. When an overloadable system function, such as diff, expand, or float, encounters an object of type DOM_FUNC_ENV, it searches the function environment for a corresponding slot.
A function environment consists of three operands. The first operand is a procedure that computes the return value of a function call. The second operand is a procedure for printing a symbolic function call on the screen. The third operand is a table that specifies how the system functions handle symbolic function calls.