How do I restore a function I accidentally overrode (heaviside function)?

I stupidly named my script heaviside and this caused the program to override the function heaviside that i desired to use within my scipt. How do I restore the function to its original state?

[per isakson]

Rename the script.

Answer 1

[madhan ravi]

Simple move your custom made function from the path or rename your function to some other name.