Perhaps you should try some spelling variations:
"coder lower triangular and problem" » "coder upper triangular and problem" (Expand search), "coder of triangular and problem" (Expand search), "coder the triangular and problem" (Expand search), "coder lower triangular _ problem" (Expand search), "coder lower triangulare jacq problem" (Expand search), "over lower triangular and problem" (Expand search)
"and python python python programming" » "and pythons python python programming" (Expand search), "and piton python python programming" (Expand search), "and pitons python python programming" (Expand search), "in python python python programming" (Expand search), "on python python python programming" (Expand search), "api python python python programming" (Expand search)

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• Performing a fuzzy search may retrieve terms with similar spellings: (("coder lower triangular and problem") OR ("and python python python programming"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coder lower triangular and problem\") OR (\"and python python python programming\"))".
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