how to increase the variable in a loop in TCL? -

i have following code in tcl:

set counter 1  {set 0} {$i < 3} {incr 1} {     set temp $counter     incr temp 1     incr counter 2  } 

for each loop, counter increased 2, , temp increased 1 based on value of counter, value of counter , temp is:

counter 1 temp 2 in first loop counter 3 temp 3 in second loop counter 5 temp 4 in third loop 

the expected value is:

counter 1 temp 2 in first loop counter 3 temp 4 in second loop counter 5 temp 6 in third loop 

what problem , how fix it?

it depends on use value:

set counter 1 {set 0} {$i < 3} {incr 1} {     set temp $counter     puts "a: counter = $counter, temp = $temp"     incr temp 1     puts "b: counter = $counter, temp = $temp"     incr counter 2      puts "c: counter = $counter, temp = $temp" } 

when run that, get:

 a: counter = 1, temp = 1 b: counter = 1, temp = 2 c: counter = 3, temp = 2 a: counter = 3, temp = 3 b: counter = 3, temp = 4 c: counter = 5, temp = 4 a: counter = 5, temp = 5 b: counter = 5, temp = 6 c: counter = 7, temp = 6 

it looks me want values position puts "b:…" located.