Perhaps you should try some spelling variations:
"coder coder learning propositional problem" » "coder coder learning proposition problem" (Expand search), "coder coder learning professional problem" (Expand search), "coder coder warning proportional problem" (Expand search), "coder codes learning propositional problem" (Expand search), "coder modern learning propositional problem" (Expand search), "coder model learning propositional problem" (Expand search), "coder decoder learning propositional problem" (Expand search), "code code learning propositional problem" (Expand search), "decoder codec learning propositional problem" (Expand search)
"on python python python programming" » "on pythons python python programming" (Expand search), "on piton python python programming" (Expand search), "on pitons python python programming" (Expand search), "in python pythin python programming" (Expand search), "of python pythof python programming" (Expand search), "_ python pyth_ python programming" (Expand search)

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("coder coder learning propositional problem") OR ("on python python python programming"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coder coder learning propositional problem\") OR (\"on python python python programming\"))".
• Removing quotes may allow a broader search: (( coder coder learning propositional problem ) OR ( on python python python programming )).
• Adding a wildcard symbol may retrieve word variants: (("coder coder learning propositional problem") OR ("on python python python programming"))*.