Question: How do I determine why Maple Hangs, when there is no obvious reason.

It hangs are v(x) := for some reason.

NULL;

q := x -> v1*Dirac(x - a1) + v2*Dirac(x - a2) + v3*Dirac(x - a3);
NULL;

V := x -> -int(q(x), x = 0 .. x) + Ra + Rb*Dirac(x - L);
proc (x) options operator, arrow, function_assign; Units:-Simple\

  :-`+`(Units:-Simple:-`+`(Units:-Simple:-`-`(MTM:-int(q(x), x 

   = 0 .. x)), Ra), Units:-Simple:-`*`(Rb, Dirac(Units:-Simple:-\

  `+`(x, `-`(L))))) end proc

NULL;

M := x -> int(V(x), x = 0 .. x) + Ma + Mb*Dirac(x - L);
proc (x) options operator, arrow, function_assign; Units:-Simple\

  :-`+`(Units:-Simple:-`+`(MTM:-int(V(x), x = 0 .. x), Ma), 

   Units:-Simple:-`*`(Mb, Dirac(Units:-Simple:-`+`(x, 

   `-`(L))))) end proc

theta := x -> 1000000000000*(int(M(x), x = 0 .. x) + `θa` + `θb`*Dirac(x - L))/(E*S_mm);
proc (x) options operator, arrow, function_assign; Units:-Simple\

  :-`*`(Units:-Simple:-`+`(Units:-Simple:-`+`(MTM:-int(M(x), x 

   = 0 .. x), `θa`), Units:-Simple:-`*`(`θb`, 

   Dirac(Units:-Simple:-`+`(x, `-`(L))))), 1/(E*S_mm*10^(-12))) 

   end proc

v := x -> int(theta(x), x = 0 .. x);
proc (x) options operator, arrow, function_assign; MTM:-int(thet\

  a(x), x = 0 .. x) end proc