kill(all)$

fluid : appendix ,levi-civita symbol ,version 1.0.
peter.vlasschaert@gmail.com,28/05/2019

formula : ε
                     i,j,k
============ 
rem :permutation tensor.

cevi_levita(i,j,k):= (i-j)*(j-k)*(k-i)/2;

cevi_levita(1,2,3);

cevi_levita(1,2,1);

cevi_levita(1,3,2);

symbol : i,j
=========

code: 

cevi_levita2(i,j):=block([],
  if i=j  then 0
    else  
    (j-i)/abs(j-i));

cevi_levita2(2,1);

cevi_levita2(2,2);

symbol:i,j,k
==========

cevi_levita3(i,j,k):=block([],    
    if  i = j  or k = j or k=i then 0
     else
    ((j-i)/abs(j-i))*((k-i)/abs(k-i))*((k-j)/abs(k-j)) );

cevi_levita3(1,2,3);

cevi_levita3(1,3,2);

cevi_levita3(3,3,3);

cevi_levita3(1,3,1);

general equation :  
===============
how to program : ?