>a¶ ↑
1 a 1 a | a 0 b
>a|b¶ ↑
1 a 1 b 1 a | b 0 a{0} 0 b{0}
>a | b | a¶ ↑
1 a 1 b 1 a | b 1 b | a 1 a | b | b 1 a | b | a 1 b | a | b
>a,a¶ ↑
1 a,a 0 a 0 a,a,a
>a{0,3}¶ ↑
1 a{3} 1 a 1 a,a,a 1 a{1,3}
>(a|b){0,4}¶ ↑
1 a 1 b 1 a,b 1 a,b,a,b 0 b,a,b,a,b 1 b,a{1,3} 1 a{1,3},b 0 a{1,3},b,a 0 a{1,4},b 0 a{0,5} 1 (b|a){0,4} 0 (b|a){0,4},a 1 (a,b){0,2} 1 (a,b){0,1},b
> a*¶ ↑
1 a 1 a? 1 a+ 1 a* 1 a{0}
> a+¶ ↑
1 a 0 a? 1 a+ 0 a* 1 a?,a 1 a,a* 1 a*,a 1 a?,a*,a 1 a*,a?,a
>(a|b)*¶ ↑
1 a 1 b 1 a,b 1 a,b,a,b 1 (b|a){0,4} 1 (b|a){0,4},a 1 a* 1 b* 1 (a|b)* 1 a{1,3} 1 b,a{1,3} 1 a{1,3},b 1 a*,(a|b)* 1 a*,b{2,5} 1 a*,(a|b)*,b{2,5}
>(a|b)+,(c|d)¶ ↑
1 a+,c 0 a*,c 1 a,c 1 a,b*,a*,c # more complex
>(a|b),(a|c){0,100}¶ ↑
1 a{0,100},(a|c) 0 a{0,101},(a|c) # the example from cmsmcq at extreme markup 05
>(a, ((b, c, d){0,5}, e{0,1}){0,4}, f)¶ ↑
1 (a, b, (c, d, b){2,3}, c, d, e, f)