'BEGIN' 'COMMENT' LIBRARY 1; 'INTEGER' NN; 'SWITCH' A := B[1], B[2]; 'SWITCH' B := A[G], A[2]; 'INTEGER''PROCEDURE' F(N, S); 'VALUE' N; 'INTEGER' N; 'SWITCH' S; 'BEGIN' NN := N; 'GOTO' S[1]; F := NN 'END'; 'INTEGER''PROCEDURE' G; 'BEGIN' 'INTEGER' N; N := NN; G := 0; NN := 'IF' N <= 1 'THEN' N 'ELSE' F(N - 1, A) + F(N - 2, A) 'END'; OUTREAL(99, F(20, A)) 'END'