# Syntactic analysis
In the syntactic analysis step, the expl3 analysis tool converts the list of `\TeX`{=tex} tokens into a tree of function calls.
## Unexpected function call argument {.e label=e300}
A function is called with an unexpected argument.
/e300-02.tex
Partial applications are detected by analysing closing braces (`}`) and do not produce an error:
/e300-01.tex
## End of expl3 part within function call {.e label=e301}
A function call is cut off by the end of a file or an expl3 part of a file:
/e301.tex
## Unbraced n-type function call argument {.w label=w302}
An n-type function call argument is unbraced:
/w302.tex
Depending on the specific function, this may or may not be an error.
## Braced N-type function call argument {.w label=w303}
An N-type function call argument is braced:
/w303.tex
Depending on the specific function, this may or may not be an error.
## Unexpected parameter number {.e label=e304}
A parameter or replacement text contains parameter tokens (`#`) followed by unexpected numbers:
/e304-01.tex
/e304-02.tex
### Expanding an unexpandable variable or constant {.t label=t305}
A function with a `V`-type argument is called with a variable or constant that does not support `V`-type expansion [@latexteam2024interfaces, Section 1.1].
