input_case nil$ m:=2$ % Nonlinear oscillator eigenstates % -------------------------------- array d(m),dp(m); operator x,c,de,ket; factor ket; on rat; x(1,1):=sqrt((n+1)/2)$ x(1,-1):=sqrt(n/2)$ x(1,0):=0$ for k:=2:m+2 do for j:=-k:k do x(k,j):= (if j1-k then sub(n=n+j,x(1,-1))*x(k-1,j-1) else 0); for k:=3:m+2 do for j:=-k:k do x(k,j):=c(k-2)*x(k,j); procedure v(l,j,a); << dp(m-l):=dp(m-l)+a*ket(n+j); if l>$ v(m,0,1)$ for k:=1:m do << de(k):=d(k); write dp(k):=dp(k) >>; end;