TY - JOUR
T1 - On the strength of marriage theorems and uniformity
AU - Fujiwara, Makoto
AU - Higuchi, Kojiro
AU - Kihara, Takayuki
PY - 2014
Y1 - 2014
N2 - Kierstead showed that every computable marriage problem has a computable matching under the assumption of computable expanding Hall condition and computable local finiteness for boys and girls. The strength of the marriage theorem reaches WKL0 or ACA0 if computable expanding Hall condition or computable local finiteness for girls is weakened. In contrast, the provability of the marriage theorem is maintained in RCA even if local finiteness for boys is completely removed. Using these conditions, we classify the strength of variants of marriage theorems in the context of reverse mathematics. Furthermore, we introduce another condition that also makes the marriage theorem provable in RCA0, and investigate the sequential and Weihrauch strength of marriage theorems under that condition.
AB - Kierstead showed that every computable marriage problem has a computable matching under the assumption of computable expanding Hall condition and computable local finiteness for boys and girls. The strength of the marriage theorem reaches WKL0 or ACA0 if computable expanding Hall condition or computable local finiteness for girls is weakened. In contrast, the provability of the marriage theorem is maintained in RCA even if local finiteness for boys is completely removed. Using these conditions, we classify the strength of variants of marriage theorems in the context of reverse mathematics. Furthermore, we introduce another condition that also makes the marriage theorem provable in RCA0, and investigate the sequential and Weihrauch strength of marriage theorems under that condition.
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U2 - 10.1002/malq.201300021
DO - 10.1002/malq.201300021
M3 - Article
AN - SCOPUS:84899904981
SN - 0942-5616
VL - 60
SP - 136
EP - 153
JO - Mathematical Logic Quarterly
JF - Mathematical Logic Quarterly
IS - 3
ER -