Name: Anonymous 2010-05-08 10:54
Some people when confronted with an miopia think "I'll wear glasses", now they have four eyes.
(3 4)
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((1 2) 3 4)┏━━━┳━━━┓ ┏━━━┳━━━┓ ┏━━━┳━━━┓
────►┃ ● ┃ ●─╂─────────────────►┃ ● ┃ ●─╂───►┃ ● ┃ ╱ ┃
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(1 2) ┏━━━┳━━━┓ ┏━━━┳━━━┓ ┏━━━┓ ┏━━━┓
────►┃ ● ┃ ●─╂───►┃ ● ┃ ╱ ┃ ┃ 3 ┃ ┃ 4 ┃
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┃ 1 ┃ ┃ 2 ┃
┗━━━┛ ┗━━━┛(cons (list 1 2) (list 3 4)).