∑■

#proof #halmos #tombstone #end of proof #demonstrandum #conclusion

📐∑✅

#proof #conclusion #demonstrandum #end of proof #summation

✅□

#QED symbol #halmos symbol #tombstone #end of proof #demonstrated #proof complete

📄∎/◾️

#end of proof #qed #halmos #formal end #final mark #tombstone symbol #mathematical ending #documentation end