# Pr\"ufer ring

## Primary tabs

Defines:
Pr\"ufer ring, coefficient module, Gaussian ring
Keywords:
fractional ideal, invertible ideal, inverse ideal
Major Section:
Reference
Type of Math Object:
Theorem

## Mathematics Subject Classification

### Lowew index

Please, tell me, how I can do the lower index "fg"
in my object Â«PrÃ¼fer ringÂ» on the right hand side of the first formula?
That is, there should be "M" with the product "fg" as lower index.
I have tried the form M_f_g, but it gives the error message "double index". Now I have written M_fg, but this does not give the right result.
pahio

M_{fg}

### Re: Lower index

Thank you very much!