It would be nice to transform a bit the mathML for functionDefinition.
Instead of displaying :
lambda(A, B, A + B)
F(A, B) = A + B (where F is the id of the functionDefinition)
Do that for both equations if possible (the image and the string).
Also, this way we display the id of the functionDefinition, otherwise, the id is never visible in the interface and it is difficult if they are many functions and their id is not related easily to their name to see in other equation which function is used.