hat
Si nou di x se domèn a, si se sa rele a etabli dè valè tout nou kapab mete nan x, Et sa a tout a etabli dè valè ki kapab y ale ou ki kapab y, puis yon valè x ne pwodwi de valè de y.
eng
If we say x is the domain, if this is the set of all values we can put into x, and this all the set of values that can go into y or that can be y, then one value of x can't produce two values of y.