In the SOFiSTiK 2023 manual §2.2.16, the use of functions are defined and exemplified:

```
LET#F '=FUN(var,formulaexpression)'
! e.g.
LET#F '=FUN(x,3*#x**3-2*#x**2+5*#x)'
LET#1 #F(1.234)
```

Is it in any way possible to make functions with multiple variables? e.g.:

```
LET#F '=FUN(x,y,2+#x+#y)'
LET#1 #F(2,3)
```

If so, what is the syntax?

Because what I’m writing isn’t working