This applet shows that any function can be implemented with sum of the sufficient number of Gaussian functions.

1) First select TARGET FUNCTION.
2) Then by changing mean values (xu1,xu2....), variances(var1,var2,....) and connection weigths (w0,w1,w2,...) try to obtain the function shown in white color. DO NOT FORGET TO PRESS ENTER AFTER CHANGING THE VALUES (for the changes to take effect).
3) If you can't find the correct values use Show Mean, Show Variance, Show Weight buttons to get the answer.