radialGradient's fx/fy attributes and a xlink:href reference

Dear SVG WG,

The spec says that if radialGradient's fx/fy attribute is not specified it takes 
the value of the cx/cy attribute. However, the spec also says that if an 
attribute isn't present when an xlink:href references another gradient the 
attribute will be "inherited" from the referenced gradient. Which behavior takes 
precedence when a radialGradient element doesn't have an fx/fy attribute but it 
does reference another radialGradient element? Clarification would be much 
appreciated.

Regards,
Jonathan