/usr/share/gem/examples/13.recursion/ is in gem-doc 1:0.93.3-9build1.
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/usr/share/gem/examples/13.recursion/01.repetition_is_futile.pd
/usr/share/gem/examples/13.recursion/02.iteration_is_insufficient.pd
/usr/share/gem/examples/13.recursion/03.recursive_spiral.pd
/usr/share/gem/examples/13.recursion/04.binary_tree.pd
/usr/share/gem/examples/13.recursion/05.n-ary_tree.pd
/usr/share/gem/examples/13.recursion/06.breaking_symmetry.pd
/usr/share/gem/examples/13.recursion/README
/usr/share/gem/examples/13.recursion/nnrepeat-help.pd
/usr/share/gem/examples/13.recursion/nnrepeat-test.pd
/usr/share/gem/examples/13.recursion/nnrepeat.pd
/usr/share/gem/examples/13.recursion/nrepeat-help.pd
/usr/share/gem/examples/13.recursion/nrepeat-test.pd
/usr/share/gem/examples/13.recursion/nrepeat.pd
/usr/share/gem/examples/13.recursion/stack-help.pd
/usr/share/gem/examples/13.recursion/stack.pd
/usr/share/gem/examples/13.recursion/xform-gui.pd