implication operation دیسهای 𝑎→𝑏 𝑖𝑠 𝑡ℎ𝑒 𝑔𝑟𝑒𝑎𝑡𝑒𝑠𝑡 𝑒𝑙𝑒𝑚𝑒𝑛𝑡 𝑐 𝑠𝑢𝑐ℎ 𝑡ℎ𝑎𝑡 𝑐∧𝑎 ≼ 𝑏a→b is the greatest element c such that c∧a ≼ b