user: You are a structured reasoning expert tasked with solving problems step by step. 
You first think about the reasoning process in the mind and then provide the answer. The reasoning process and answer should be enclosed within <think> </think> and <answer> </answer> tags, respectively, i.e., <think> reasoning process here </think> <answer> answer here </answer>. 
Given a question and the associated knowledge graph triplets (entity, relation, entity), you are asked to answer the question with these triplets and your own knowledge. 
You can break down the original question into several sub-questions and explore the given knowledge graph to solve them step-by-step. If there are multiple possible answers, choose one as the final answer. 
After thinking, when you finally reach a conclusion, clearly state the answer within <answer> </answer> tags, i.e., <answer> answer here </answer>. 
Question: what video game engine did tim gilberts develop? 
Knowledge Triplets: Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, Los Vientos del Walhalla
The Quill, cvg.computer_game_engine.successor_engine, Professional Adventure Writer
Professional Adventure Writer, cvg.computer_game_engine.predecessor_engine, The Quill
Professional Adventure Writer, cvg.computer_game_engine.developer, Tim Gilberts
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, Los Extraordinarios Casos del Dr. Van Halen Caso 5: Ultimo Acto
m.05gjhjf, award.award_honor.honored_for, Professional Adventure Writer
The Challenge of Iythus, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, Los Extraordinarios Casos del Dr. Van Halen Volumen 2 Relato II: Las Ruedas de Ezequiel
Los Extraordinarios Casos del Dr. Van Halen Caso 4: Tristes Alas del Destino, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Professional Adventure Writer, computer.software.languages_used, Assembly language
On Reflection, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, Los Extraordinarios Casos del Dr. Van Halen Caso 4: Tristes Alas del Destino
Tim Gilberts, computer.software.developer, Professional Adventure Writer
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, Codigo Secreto Lucybel: Cryogenic
Abracadabra, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, Los Extraordinarios Casos del Dr. Van Halen Volumen 2 Relato I: Las Calles del Miedo
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, Codigo Secreto Lucybel: Apocalypse
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, Los Extraordinarios Casos del Dr. Van Halen Caso 2: El Cuervo de la Tormenta
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, On Reflection
The Dream Concert, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Los Extraordinarios Casos del Dr. Van Halen Caso 1: Misterio en la Catedral, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Professional Adventure Writer, award.award_winning_work.awards_won, m.05gjhjf
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, Los Extraordinarios Casos del Dr. Van Halen Volumen 2 Relato III: El Hijo del Crepusculo
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, Codigo Secreto Lucybel: Evilution
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, Abracadabra
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, Jack the Ripper
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, The Dream Concert
Codigo Secreto Lucybel: Evilution, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Professional Adventure Writer, cvg.computer_game_engine.developer, Graeme Yeandle
Los Extraordinarios Casos del Dr. Van Halen Volumen 2 Relato II: Las Ruedas de Ezequiel, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Gilsoft, cvg.computer_game_engine_developer.computer_game_engines_developed, Professional Adventure Writer
Professional Adventure Writer, cvg.computer_game_engine.developer, Gilsoft
Codigo Secreto Lucybel: Apocalypse, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Professional Adventure Writer, computer.software.first_released, 1986
Professional Adventure Writer, computer.software.license, Proprietary software
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, The Raven
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, Los Extraordinarios Casos del Dr. Van Halen Caso 1: Misterio en la Catedral
Los Extraordinarios Casos del Dr. Van Halen Caso 2: El Cuervo de la Tormenta, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Tim Gilberts, computer.software_developer.software, Professional Adventure Writer
Los Vientos del Walhalla, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Graeme Yeandle, computer.software_developer.software, Professional Adventure Writer
Los Extraordinarios Casos del Dr. Van Halen Volumen 2 Relato III: El Hijo del Crepusculo, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Codigo Secreto Lucybel: Cryogenic, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Jack the Ripper, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
m.04yk454, computer.software_compatibility.software, Professional Adventure Writer
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, Los Extraordinarios Casos del Dr. Van Halen Caso 3: Cantos de Anubis
Professional Adventure Writer, computer.software.developer, Graeme Yeandle
Professional Adventure Writer, computer.software.developer, Tim Gilberts
The Raven, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Tim Gilberts, cvg.computer_game_engine_developer.computer_game_engines_developed, Professional Adventure Writer
Graeme Yeandle, cvg.computer_game_engine_developer.computer_game_engines_developed, Professional Adventure Writer
Professional Adventure Writer, computer.software.compatible_oses, m.04yk454
Los Extraordinarios Casos del Dr. Van Halen Caso 3: Cantos de Anubis, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Professional Adventure Writer, base.zxspectrum.zx_spectrum_program.wos_id, 0006825
Professional Adventure Writer, computer.software.developer, Gilsoft
Los Extraordinarios Casos del Dr. Van Halen Volumen 2 Relato I: Las Calles del Miedo, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Dark Tower, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, The Challenge of Iythus
Gilsoft, computer.software_developer.software, Professional Adventure Writer
Los Extraordinarios Casos del Dr. Van Halen Caso 5: Ultimo Acto, cvg.computer_videogame.uses_game_engine, Professional Adventure Writer
Professional Adventure Writer, cvg.computer_game_engine.used_for_computer_games, Dark Tower

Answer: Professional Adventure Writer