# Question 33106: Addition of Equal-Size Matrices [Return to catalogue page 166](https://ocme.evemisslab.com/en/questions/page/166/) [← Question derivation index](https://ocme.evemisslab.com/en/questions/) · [Original question batch](https://ocme.evemisslab.com/en/practice/batch-20261006-advance-20261007-r01-matrix-foundations/#q-20261006-advance-20261007-r01-matrix-0056) This teaching derivation has second-context AI mathematical and bilingual semantic review, limited to the model and assumptions stated in this question. It has no human review or new Lean proof and does not promote the original question or MKO to Canonical truth. R0065-33106 · q-20261006-advance-20261007-r01-matrix-0056 ## Original question and givens Over R, A=[[-7], [-5]] and B=[[-2], [-1]] have the same dimensions. Find A+B as a nested list of rows. - G001 — Over R, A=[[-7], [-5]] and B=[[-2], [-1]] have the same dimensions. Find A+B as a nested list of rows. ## Definition and scope Use the original question domain, assumptions and cited MKO definitions. This item has second-context mathematical and bilingual review, with the model, answer and every arithmetic step independently recomputed from the original parameters; the source question remains a candidate. - [mko-matrix](https://ocme.evemisslab.com/en/mko/mko-matrix/) ## Step-by-step derivation S001 · impliesBefore source roles = [qf-matrix-addition, matrix_addition, reals, []] After derived = [[nested_ROW_matrix]] Conditions: none MOD25 uses LOCAL hyphens/named domains,legacy matrices underscores/reals;BASE logic acquires no domain/op.Output tuples,matrices,numeric fields and fraction texts follow THIS source,not a universal/1 rule.Retain originals/English/AST/status. Step identifiers and dependenciesRule: R65_SOURCE_bank_keys_operation_domain_ordered_output_roles · Uses: G001 S002 · impliesBefore source roles = [A ORIGINAL, [[-7], [-5]]] After derived = [2, 1] Conditions: none THIS bank allows1..5 by1..5 matrices,not the R64 2×2 restriction.Type EVERY raw SAFE cell,including unused shape/entry cells.Keep original row order. Step identifiers and dependenciesRule: Matrix_RAW_rectangular_1to5_ALL_SAFE_entries_even_unused · Uses: G001, S001 S003 · impliesBefore source roles = [B ORIGINAL, [[-2], [-1]]] After derived = [2, 1] Conditions: none THIS bank allows1..5 by1..5 matrices,not the R64 2×2 restriction.Type EVERY raw SAFE cell,including unused shape/entry cells.Keep original row order. Step identifiers and dependenciesRule: Matrix_RAW_rectangular_1to5_ALL_SAFE_entries_even_unused · Uses: G001, S002 S004 · calculationBefore Matrix sum ORIGINAL entry0,0 := sum(-7, -2) After Matrix sum ORIGINAL entry0,0 = -9 Conditions: none Use ORIGINAL operands/order for exact arithmetic.Rational operations separately enforce this MOD25 SOURCE pre-reduction envelope.Do not globally cap every derived integer at one million or use floating approximations. Step identifiers and dependenciesRule: exact_rational_arithmetic · Uses: G001, S003 S005 · calculationBefore Matrix sum ORIGINAL entry1,0 := sum(-5, -1) After Matrix sum ORIGINAL entry1,0 = -6 Conditions: none Use ORIGINAL operands/order for exact arithmetic.Rational operations separately enforce this MOD25 SOURCE pre-reduction envelope.Do not globally cap every derived integer at one million or use floating approximations. Step identifiers and dependenciesRule: exact_rational_arithmetic · Uses: G001, S004 S006 · impliesBefore source roles = [[[-7], [-5]], [[-2], [-1]]] After derived = [[[-9], [-6]]] Conditions: none Add EVERY corresponding entry ONLY at equal shapes.Derived sums may exceed SAFE;do not reparse as a RAW matrix.No zero-padding or broadcasting. Step identifiers and dependenciesRule: Matrix_ADDITION_all_corresponding_entries_NO_padding_or_raw_recap · Uses: G001, S005 ## Reverse checks - S006 · premise_and_result_audit — Reverse-check ORIGINAL data,types,ordered roles,domain and premises;the conclusion need not uniquely recover its premises.Keep finite source candidates,independent review,formal proof and publication separate. - S005 · premise_and_result_audit — Recompute Matrix sum ORIGINAL entry1,0 with exact rational arithmetic, not rounded decimals. - S004 · premise_and_result_audit — Recompute Matrix sum ORIGINAL entry0,0 with exact rational arithmetic, not rounded decimals. - S003 · premise_and_result_audit — Reverse-check ORIGINAL data,types,ordered roles,domain and premises;the conclusion need not uniquely recover its premises.Keep finite source candidates,independent review,formal proof and publication separate. - S002 · premise_and_result_audit — Reverse-check ORIGINAL data,types,ordered roles,domain and premises;the conclusion need not uniquely recover its premises.Keep finite source candidates,independent review,formal proof and publication separate. - S001 · premise_and_result_audit — Reverse-check ORIGINAL data,types,ordered roles,domain and premises;the conclusion need not uniquely recover its premises.Keep finite source candidates,independent review,formal proof and publication separate. ## Result [[-9], [-6]] The full substitutions and premise checks give the original answer; source identity,format and status are unchanged. ## This question review and source binding Review date: 2026-10-26 Original questions, answers, step expressions, numeric ASTs and historical records are retained. Source candidate labels remain historical and are not overwritten as formal proof. Source hashes and review receipts - input commit: 0f7be61e2c22317a4075561dc822c87d881a50db - original question SHA-256: c14e5d0f5c004bf6eeb3bca119a015dd12fadc2dd1e73c373149897fa6f90163 - candidate record SHA-256: 73f1c9b0ac04183e28674bcc76f7ed8cb3d89c4198f4978b11b914ac99ee414d - semantic review receipt SHA-256: 92bb5fa69818f30cd2806d74a26bd5ede6c48c80d2ecc3d31a5130d4ad7666b6 - question-first witness SHA-256: 012b5aa905280d616be49aa9462daaa73bf7f6247d0a796e78bc5bcd24e6bd00 - Lean: NOT_RUN · human review: NOT_PERFORMED [Same-source full JSON](https://ocme.evemisslab.com/data/question-derivations/questions/q-20261006-advance-20261007-r01-matrix-0056.json)