LaTeX not work as for '\exist'

[EvelynLuo]

trafficstars

Hi, \exist doesn't work in LaTeX I wrote : ${ A| \exist C\in Country \exist L \in geo_Lake (C.code = L.country \land A.name = C.name) }$ hope to see : but shown:

[tarlety]

LaTeX syntax is supported by mathjax.

Please use exists for exist symbol.

Symbols list can be found here: https://docs.mathjax.org/en/latest/input/tex/macros/index.html