\geqslant Undefined control sequence in Latex
When I compile the following latex code:
begin{align}
f_{m}(x) = c_{1,m} times I(x_{i}^{m} geqslant t_{m} ) + c_{2,m} times I(x_{i}^{m} < t_{m} ),
end{align}
I always get an error:
! Undefined control sequence.
<argument> ..._{1,m} times I(x_{i}^{m} geqslant
t_{m} ) + c_{2,m} times I...
l.124 end{align}
When I replace geqslant with >=, it is okay.
I already include the amsmath package. What would cause the problem?
Thanks and regards!
该命令没有在amsmath包中定义，而是amssymb包 - 在您的序言中放置usepackage{amssymb} ，您应该没问题。