:: deftheorem Def3 defines RemLAPLACE:def 3 : for i, n being Nat for perm being Element of Permutations(n + 1) st i inSeg(n + 1) holds for b4 being Element of Permutations n holds ( b4=Rem (perm,i) iff for k being Nat st k inSeg n holds ( ( k < i implies ( ( perm . k < perm . i implies b4. k = perm . k ) & ( perm . k >= perm . i implies b4. k =(perm . k)- 1 ) ) ) & ( k >= i implies ( ( perm .(k + 1)< perm . i implies b4. k = perm .(k + 1) ) & ( perm .(k + 1)>= perm . i implies b4. k =(perm .(k + 1))- 1 ) ) ) ) );