nl_tokens: function to compute term P of U V W ( Table II )
pl_tokens: function P ( i , l , a , b , R_1 , R_lm1 ) { var ri1 , rim1 , ri0 , ret ; ri1 = R_1 [ i + 1 ] [ 1 + 1 ] ; rim1 = R_1 [ i + 1 ] [ - 1 + 1 ] ; ri0 = R_1 [ i + 1 ] [ 0 + 1 ] ; if ( b == - l ) { <mask> = ri1 * R_lm1 [ a + l - 1 ] [ 0 ] + rim1 * R_lm1 [ a + l - 1 ] [ 2 * l - 2 ] ; } else { if ( b == l ) ret = ri1 * R_lm1 [ a + l - 1 ] [ 2 * l - 2 ] - rim1 * R_lm1 [ a + l - 1 ] [ 0 ] ; else ret = ri0 * R_lm1 [ a + l - 1 ] [ b + l - 1 ] ; } return ret ; }