https://github.com/akkartik/mu1/blob/master/counters.mu
 1 # example program: maintain multiple counters with isolated lexical scopes
 2 # (spaces)
 3 
 4 def new-counter n:num -> default-space:space [
 5   default-space <- new location:type, 30
 6   load-inputs  # initialize n
 7 ]
 8 
 9 def increment-counter outer:space/names:new-counter, x:num -> n:num/space:1 [
10   local-scope
11   load-inputs
12   0:space/names:new-counter <- copy outer  # setup outer space; it *must* come from 'new-counter'
13   n/space:1 <- add n/space:1, x
14 ]
15 
16 def main [
17   local-scope
18   # counter A
19   a:space/names:new-counter <- new-counter 34
20   # counter B
21   b:space/names:new-counter <- new-counter 23
22   # increment both by 2 but in different ways
23   increment-counter a, 1
24   b-value:num <- increment-counter b, 2
25   a-value:num <- increment-counter a, 1
26   # check results
27   $print [Contents of counters], 10/newline
28   $print [a: ], a-value, [ b: ], b-value, 10/newline
29 ]