how to place a tilde under a symbol in math mode

[richard noel fell]

I have installed the accents.sty package in the hopes of being able to
place a symbol, such as a tilde, underneath a letter. However, latex
does not like me doing that and I get a missing $ error message for a
construct such as $\underaccent{{\tilde}{x}}$. Does anyone have any
idea what I might have done wrong or perhaps an alternative strategy?
Many thanks,
Dick Fell

[Lars Madsen]

Post by richard noel fell
I have installed the accents.sty package in the hopes of being able to
place a symbol, such as a tilde, underneath a letter. However, latex
does not like me doing that and I get a missing $ error message for a
construct such as $\underaccent{{\tilde}{x}}$. Does anyone have any
idea what I might have done wrong or perhaps an alternative strategy?
Many thanks,
Dick Fell

I haven't tried accents or \underaccent, but isn't the syntax a bit off,
shouldn't it be

$\underaccent{\tilde}{x}$

?

[Donald Arseneau]

$\underaccent{{\tilde}{x}}$. Does anyone have any idea what I might have

\undertilde{x}