== !MadGraph5 Syntax for process generation ==

Most of the [http://madgraph.phys.ucl.ac.be/EXAMPLES/example.html MG4 syntax] is kept unchanged, but in MG5,
   1. All particles should be separated with a spaces
{{{
write this:
   w+ > ve e+
and not:
   w+>vee+
}}}
   2. The coupling order is specified after the process, on the same line. 
      Please note that:
        a. Note that contrary to MG4 the default coupling order is infinity
        b. couplings are case sensitive
{{{
write this:
   p p > ve e+ j j QED=2
and not:
   p p > ve e+ j j qed=2 qcd=99
}}}
   3. Other special process definition tags are the same:
      a. "p p > w+ > j j j" allows only diagrams with a W+ as an s-channel propagator
      b. "e+ e- > e+ e- / z" forbids Z to appear in any internal line in the process
      c. "p p > ul ul~ j $ go"  forbids go to appear in any s-channel propagator

   4. *The syntax for decay chain is different.*
      a. In MG5 the production process is separated from the decays by a comma. 
      b. Each subprocess (core process or decay) can have coupling orders/special tag restrictions
{{{
write this:
   g g > t t~ / a QED=0, (t > b W+, W+ > l+ vl), t~ >j j j QCD=0
and not:
   g g > (t > b (W+ > l+vl))(t~ > j j j)      
}}}
   Note that if you run MG5 using an MG4 proc_card, then the coupling orders will act as in MG4.