[CAS] Detection of errors in the program editor

[compsystems]

Hello,

1: why the sentence "if ( (a:= 5) and true) then" this has the final state TRUE?, the left side of the comparison is an assignment, why evaluates to true?

PHP Code:

#cas
  test( ):=
begin
  print;
  //print (5 != 6);
  //print (5 <> 6);
  //print (5 ≠ 6);

  if ( (a:= 5) and true) then
    print("yes");
  else
    print("no");
  end;
  return "Done";
end;
#end 


test( ); returns "YES"