| # Starting from sed 4.1.3, regexes are compiled with REG_NOSUB | |
| # if they are used in an address, so that the matcher does not | |
| # have to obey leftmost-longest. The tricky part is to recompile | |
| # them if they are then used in a substitution. | |
| /\(ab*\)\+/ s//>\1</g |