Do away with the old and set up the new. Ge and ding are two trigrams in The Book of Changes. The ge trigram implies change of an unsuitable old state of affairs. The ding trigram signifies the creation of new things. Following the doctrine in Commentary on The Book of Changes, later people combined the two together to represent an outlook advocating changes.
引例
革，去故也；鼎，取新也。（《周易·杂卦》）（革卦，意味着革除往事物。鼎卦，意味着创建新事物。）
Ge trigram signifies doing away with the old; ding trigram symbolizes setting up the new. (The Book of Changes)
