5.5 How to display a build in function code?

Some examples

interface(verboseproc=3); 
print(DEtools) 
print(`ODEtools/symgen`); 
print(`symgen/methods`); 
print(`symgen/do`);
 

To stop the debugger at symgen do

stopat(`ODEtools/symgen`);
 

To get infolevel on symgen do

infolevel[`symgen`]:=5;
 

Or to see line numbers

interface(verboseproc=3); 
showstat(dsolve)
 

Or can use the Browse(); command

with(LibraryTools); 
Browse();
 

Another option I found is

s:=debugopts(procdump=`showstat`);
 

Then the above produces listing that can be copied as string with line wrapping ok.