[Om] Specification of functions, preserving function signatures

[Andreas Franke]

W Naylor wrote:

><OMBIND>
>  <OMS cd="fns1" name="lambda"/>
>...
>
>however this holds no typing information. One possible solution is to use 
>attribution where the attribute is 
><OMS cd="ecc" name="type"/>
>this has role 'semantic-attribution' so preserves semantic information, an 
>example would be f:Z->N x +-> x^2 as
>  
>
I think in Omega we use an attribution method for specifying the type of
lambda-bound variables, see e.g.
http://mbase.mathweb.org:8080/mbase/showItemXML?mid=10838

          <OMBIND>
            <OMS cd="fns1" name="lambda" />
            <OMBVAR>
              <OMATTR>
                <OMATP>
                  <OMS cd="simpletypes" name="type" />
                  <OMS cd="NATURAL" name="NUM" />
                </OMATP>
                <OMV name="X" />
              </OMATTR>
            </OMBVAR>
            ...
          </OMBIND>

We don't use that mechanism to specify the type of the result expression, 
however.

HTH,
Andreas