Categories:
functions triggers variables
Functions: all aff other char array room obj quest int string

Array functions:

test if variable is still valid
test if string is valid
return allways 1 when argument is int
test if object is valid
test if affect is valid
test if array is valid

Syntax:

(int) valid(char)
(int) valid(string)
(int) valid(int)
(int) valid(obj)
(int) valid(aff)
(int) valid(array)

Examples:

if (valid(ch)) ...