15 research outputs found

    On uniform relationships between combinatorial problems

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    The enterprise of comparing mathematical theorems according to their logical strength is an active area in mathematical logic, with one of the most common frameworks for doing so being reverse mathematics. In this setting, one investigates which theorems provably imply which others in a weak formal theory roughly corresponding to computable mathematics. Since the proofs of such implications take place in classical logic, they may in principle involve appeals to multiple applications of a particular theorem, or to nonuniform decisions about how to proceed in a given construction. In practice, however, if a theorem Q implies a theorem P, it is usually because there is a direct uniform translation of the problems represented by P into the problems represented by Q, in a precise sense formalized by Weihrauch reducibility. We study this notion of uniform reducibility in the context of several natural combinatorial problems, and compare and contrast it with the traditional notion of implication in reverse mathematics. We show, for instance, that for all n; j; k 1, if j < k then Ramsey's theorem for n-tuples and k many colors is not uniformly, or Weihrauch, reducible to Ramsey's theorem for n-tuples and j many colors. The two theorems are classically equivalent, so our analysis gives a genuinely ner metric by which to gauge the relative strength of mathematical propositions. We also study Weak K�onig's Lemma, the Thin Set Theorem, and the Rainbow Ramsey's Theorem, along with a number of their variants investigated in the literature. Weihrauch reducibility turns out to be connected with sequential forms of mathematical principles, where one wishes to solve in nitely many instances of a particular problem simultaneously. We exploit this connection to uncover new points of di erence between combinatorial problems previously thought to be more closely related

    Overt choice

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    We introduce and study the notion of overt choice for countably-based spaces and for CoPolish spaces. Overt choice is the task of producing a point in a closed set specified by what open sets intersect it. We show that the question of whether overt choice is continuous for a given space is related to topological completeness notions such as the Choquet-property; and to whether variants of Michael’s selection theorem hold for that space. For spaces where overt choice is discontinuous it is interesting to explore the resulting Weihrauch degrees, which in turn are related to whether or not the space is Fréchet–Urysohn

    Morphological Analysis of Philippine Ecological Neologisms

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    Using a qualitative-descriptive design in analyzing morphological processes and structures, the present study examines the ecological neologisms used in the Philippines. Ecological, environmental, or green neologisms are newly added lexicons used in daily ecological discourses. To appraise the study's aims to identify, define, analyze, and differentiate ecological neologisms from other neologisms as used in the Philippines, the study extracted its data from the Press Release Section website of the Department of Environment and Natural Resources from January 2022 to December 2022. A total of two hundred twenty-nine (229) articles were examined for this paper. Results reveal the presence of fourteen (14) ecological neologisms in the articles: ecological integrity, urban park, climate finance, green job, green city, ecoexpert, ecofrontliner, ecodefender, climate agenda, green assessment, ecoyouth, river ranger, ecohero, and ecoinspector. Further, these neologisms are borrowed from the English vocabulary and are all classified as nouns, and are mainly used to name individuals who engage in environmental initiatives in the Philippines. Moreover, these ecological neologisms are formed through compounding and blending, following the general rule of structuring words in Standard English

    Downloaded Worksheets: A Learning Activity to Enhance Mathematical Level

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    The researcher was prompted to conduct this study to give intervention of the alarming situation which there is a low performance in solving problems related to geometry in Grade IV Mathematics. This study was about on how to enhance the mathematical competencies of the grade IV pupils using a downloaded worksheets as a learning activity. This study focused in giving remediation applying the intervention materials. These resources give several approaches to attain mastery using distinct drill cards. The investigation was carried out utilizing quasi-experimental design. During administering the pre-test and post-test, the researcher used the weighted mean and t-test to determine the mean percentage scores of the respondents. The respondents were 56 fourth grade learners enrolled in Marangog Elementary School and Tagnate Elementary School in Hilongos East District for the school year 2019 – 2020. At the end of the study, it was found out the use of downloaded math worksheets were found effective means of improving the mastery level. In addition, based on the results gathered, the downloaded math worksheets which were used in the drills or practice greatly contributed to the elimination of non-numerates, and give significantly increasing the number of pupils who mastered the competencies related to geometry. As a result, a proposed innovative teaching strategy is recommended
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