Logical syllogism — determine which conclusions follow beyond doubt. Statements: 1) Some pens are books. 2) Some books are pencils. Conclusions: (1) Some pens are pencils. (2) Some pencils are pens. (3) All pencils are pens. (4) All books are pens.

Introduction / Context:
From two independent “Some …” premises, we must avoid inferring intersections that are not guaranteed. This is a common trap in syllogisms.

Given Data / Assumptions:

• Some pens overlap books.
• Some books overlap pencils.
• No information connects the same book elements across both statements.

Concept / Approach:
Separate “Some” overlaps through a middle term (books) do not force an overlap between pens and pencils. Universal conclusions require universal premises, which are absent here.

Step-by-Step Solution:
(1) “Some pens are pencils” — could be true, but not necessary. The set of books that are pens might differ from the set of books that are pencils. (2) “Some pencils are pens” — equivalent to (1), still not necessary. (3) “All pencils are pens” — far stronger than warranted. (4) “All books are pens” — not implied since only “Some pens are books” is given.

Verification / Alternative check:
Counterexample: Let books = {b1, b2}; pens∩books = {b1}; pencils∩books = {b2}. Then both premises hold, but pens and pencils do not intersect. Thus none of the conclusions is forced.

Why Other Options Are Wrong:
Options with (1) or (2) assume an intersection that need not exist. Options with (3) or (4) falsely universalize.

Common Pitfalls:
Misapplying transitivity to “Some” statements and inferring universals from particulars.

Final Answer:
None of the four