{"title":"Infinite Wordle and the mastermind numbers","authors":"Joel David Hamkins","doi":"10.1002/malq.202200049","DOIUrl":null,"url":null,"abstract":"<p>I consider the natural infinitary variations of the games Wordle and Mastermind, as well as their game-theoretic variations Absurdle and Madstermind, considering these games with infinitely long words and infinite color sequences and allowing transfinite game play. For each game, a secret codeword is hidden, which the codebreaker attempts to discover by making a series of guesses and receiving feedback as to their accuracy. In Wordle with words of any size from a finite alphabet of <i>n</i> letters, including infinite words or even uncountable words, the codebreaker can nevertheless always win in <i>n</i> steps. Meanwhile, the <i>mastermind number</i> <math>\n <semantics>\n <mi>m</mi>\n <annotation>$\\mathbbm {m}$</annotation>\n </semantics></math>, defined as the smallest winning set of guesses in infinite Mastermind for sequences of length ω over a countable set of colors without duplication, is uncountable, but the exact value turns out to be independent of <math>\n <semantics>\n <mi>ZFC</mi>\n <annotation>$\\mathsf {ZFC}$</annotation>\n </semantics></math>, for it is provably equal to the eventually different number <math>\n <semantics>\n <mrow>\n <mi>d</mi>\n <mo>(</mo>\n <msup>\n <mo>≠</mo>\n <mo>∗</mo>\n </msup>\n <mo>)</mo>\n </mrow>\n <annotation>$\\mathfrak {d}({\\ne ^*})$</annotation>\n </semantics></math>, which is the same as the covering number of the meager ideal <math>\n <semantics>\n <mrow>\n <mrow>\n <mtext>cov</mtext>\n </mrow>\n <mo>(</mo>\n <mi>M</mi>\n <mo>)</mo>\n </mrow>\n <annotation>$\\operatorname{\\mbox{cov}}(\\mathcal {M})$</annotation>\n </semantics></math>. I thus place all the various mastermind numbers, defined for the natural variations of the game, into the hierarchy of cardinal characteristics of the continuum.</p>","PeriodicalId":49864,"journal":{"name":"Mathematical Logic Quarterly","volume":"69 4","pages":"400-416"},"PeriodicalIF":0.4000,"publicationDate":"2023-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/malq.202200049","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Mathematical Logic Quarterly","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/malq.202200049","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"LOGIC","Score":null,"Total":0}
引用次数: 2
Abstract
I consider the natural infinitary variations of the games Wordle and Mastermind, as well as their game-theoretic variations Absurdle and Madstermind, considering these games with infinitely long words and infinite color sequences and allowing transfinite game play. For each game, a secret codeword is hidden, which the codebreaker attempts to discover by making a series of guesses and receiving feedback as to their accuracy. In Wordle with words of any size from a finite alphabet of n letters, including infinite words or even uncountable words, the codebreaker can nevertheless always win in n steps. Meanwhile, the mastermind number , defined as the smallest winning set of guesses in infinite Mastermind for sequences of length ω over a countable set of colors without duplication, is uncountable, but the exact value turns out to be independent of , for it is provably equal to the eventually different number , which is the same as the covering number of the meager ideal . I thus place all the various mastermind numbers, defined for the natural variations of the game, into the hierarchy of cardinal characteristics of the continuum.
期刊介绍:
Mathematical Logic Quarterly publishes original contributions on mathematical logic and foundations of mathematics and related areas, such as general logic, model theory, recursion theory, set theory, proof theory and constructive mathematics, algebraic logic, nonstandard models, and logical aspects of theoretical computer science.