Republican Forcible Rape

Republican Vice Residential nominee, Paul Ryan, Todd Akin and 214 other Republicans co-sponsored the No Taxpayer Funding for Abortion Act which would prohibit federal funding of abortions except in instances of an act of forcible rape or, if a minor, or act of incest.

~ H.R. 3 112th Congress 2011-10-20

Just what is non-forcible rape that denies abortion?