outer mac: _u1 (hello,world) inner mac: _u1 (hello,world) outer mac: _u2 (goodbye,world) inner mac: _u2 (goodbye,world) outer rept before: _u3 inner rept before: _u3 outer for: _u4 ($0) inner for: _u4 ($0) outer for: _u5 ($1) inner for: _u5 ($1) outer for: _u6 ($2) inner for: _u6 ($2) outer rept after: _u3 inner rept after: _u3 outer rept before: _u7 inner rept before: _u7 outer for: _u8 ($0) inner for: _u8 ($0) outer for: _u9 ($1) inner for: _u9 ($1) outer for: _u10 ($2) inner for: _u10 ($2) outer rept after: _u7 inner rept after: _u7