# Evaluating the error "Can only substitute elements of positive valuation"

I'm trying to work with sage's weierstrass_p function for elliptic curves, and I'm getting an error that I can't interpret.

This is what I'm running,

```
E = EllipticCurve('11a1')
WP = E.weierstrass_p()
L = E.lseries()
WP(L(1))
```

The error I'm getting is "Can only substitute elements of positive valuation"

And I just don't know why sage doesn't want to evaluate the function at the given value. Any thoughts would be really appreciated!

WP is not a function, but a power series

Is there no way to evaluate, even if it's just a numeric approximation the power-series at a value of z?