'begin' 'comment' examine some kinds of for-loops ; 'integer' i, sum; 'real' x, y; sum := 0; 'for' i := 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 'do' sum := sum + i; 'if' sum = 55 'then' vprint ("1. ok.") 'else' vprint ("1. error", sum); sum := 0; 'for' i := 1 'step' 1 'until' 10 'do' sum := sum + i; 'if' sum = 55 'then' vprint ("2. ok.") 'else' vprint ("2. error", sum); sum := 0; 'for' i := 10 'step' -1 'until' 1 'do' sum := sum + i; 'if' sum = 55 'then' vprint ("3. ok.") 'else' vprint ("3. error:", sum); sum := 0; 'for' i := 1, i + 1 'while' i <= 10 'do' sum := sum + i; 'if' sum = 55 'then' vprint ("4. ok.") 'else' vprint ("4. error:", sum); sum := 0; 'for' i := 1, 2, 3, i + 1 'while' i <= 7, 8 'step' 1 'until' 10 'do' sum := sum + i; 'if' sum = 55 'then' vprint ("5. ok.") 'else' vprint ("5. error:", sum); 'end'