¬¬P∨¬¬Q⇒¬¬(P∨Q)
証明
https://kakeru.app/d52017eaf69c0a3a04380fccd2ed6af3 https://i.kakeru.app/d52017eaf69c0a3a04380fccd2ed6af3.svg
#2021-11-19
08:54:25