i just saw the symbol ⊆ but with two lines underneath it. i was flummoxed. really puzzled. what could it mean? if ⊂ is 'is a strict subset', ⊆ is 'is a regular subset' then maybe two means 'is a really loose and vague subset'?? i couldn't work it out. then i realised that it was just ⊆ underlined because it was a link

josef@jk@mastodon.socialgiven that ⊃ ≈ ⊇ i'd like to define ⊂++ ⊇ ⊂ in the same way that C++ ≈⊇ C