User blog comment:Googleaarex/Make an extension of the notation/@comment-5029411-20140926211035/@comment-25371339-20140930192804

a(-%-)-b = a(-&&&...&&&-)-a with b &'s

a(-%&-)-b = a(-%(-%(-%(-%...)-)-)-)-a with b levels

a(-%%-)-b = a(-%&&&...&&&-)-a with b &'s

Limit is a(-%%%...%%%-)-b