NOTA	testing embedded loops feature of class SEO_simulator. 14 ops
|   X   |   |   
|   @---+---X   
|   X   |   |   
LOOP	20	NREPS=	2
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|   @---X   |   
|   X   |   |   
    LOOP	10	NREPS=	4
@---X   |   |   
    NEXT	10
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|   @---X   |   
|   X   |   |   
NEXT	20
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|   @---+---X   
|   X   |   |   
|   |   X   |   
