How to cause error in a function intentionally??

How to cause error in a function from outside the function while its running??

Any help would be appreciated. Thanks In Advance!!

I made errors on my code intentionally, I changed function C and D

function C() priadwnt("Wolf C is not fenced") pridwant("Wolf C is enclosed with Wolf D") Tedwadxt = "Wolf C is not fenced" .. "Wolf C is enclosed with Wolf D" print("WHAT?1") end

function D() prwadint("Wolf D is not fenced") prwadint("Wolf D is enclosed with Wolf C") Texdwt = "Wolf D is not fenced" .. "Wolf D is enclosed with Wolf C" print("WHAT?2") end

this is just my example, by changing function c and d