SPUG: range operator

[Florentin]

Please help me understand how range operator works :

# cat _a
# x1
# a
# x5
# x1
# b
# x3
# c
# d

##-------------

my $start=qr/x1/;
my $end=qr/x3|x5/;

# prints all aa minus c, d  - OK
 while( <>) { if(/$start/../$end/){ print ; } }

# Expect to print only a and b --> it prints all from x1 to x3 as above
 while( <>) {
   if(/$start/+1 ../$end/-1) {
       print ;
   }
 }

# Expect to print only a and b --> prints nothing ??
 while( my $x = <>) {
      if($x=~m/$start/+1 .. $x=~m/$end/-1){
          print ;
      }
 }


Thank you.