Global Alignment With Mummer (Parameter for Gap Extension & Opening Cost)

[peveralldubois]

Dear Sir,

I am trying to perform global alignment for contigs to several
chromosomes in genome using Mummer.

I am wondering what is the parameter I can use for setting the parameter below

1. Gap Extension Cost (e.g. I want to set it to < 1).
2. Gap Opening Cost.

Specifically for "nucmer" script.

Thanks and hope to hear from you again.