势不两立

shì bù liǎng lì

irreconcilable

Character by character

势shì
situation

不bù
not

两liǎng
both

立lì
stand

这两家公司势不两立。

These two companies are sworn enemies.

Tone: neutral.

From the Stratagems of the Warring States on Chu and Qin: one's rise is the other's fall.

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