Plus icon from Tango Project Since version 0.8.90 Tango Project icons are Public Domain: Tango Project FAQ add icon externalsource Tango List Add
symbol square number math mathematics letter-i i-square imaginary Imaginary Math Symbol clip art imaginary signs & symbols symbol Symbol Square Number Math Mathematics Letter I I Square Imaginary
Minus icon from Tango Project Since version 0.8.90 Tango Project icons are Public Domain: Tango Project FAQ remove icon externalsource Tango List Remove