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% stack: xact-filename
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% create a subfolder of xact images to multipart transmit
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outchain
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% stack: xact-filename mpart-src
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second ofxact
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% stack: xact-filename mpart-src xact-spec
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rot empty chained enc^dest
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% stack: mpart-src xact-spec xact-enc-filename
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^3)
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% stack: xact-spec xact-enc-spec
%
copyfile