| Title:
             | 
On weakly monotonically monolithic spaces (English) | 
| Author:
             | 
Peng, Liang-Xue | 
| Language:
             | 
English | 
| Journal:
             | 
Commentationes Mathematicae Universitatis Carolinae | 
| ISSN:
             | 
0010-2628 (print) | 
| ISSN:
             | 
1213-7243 (online) | 
| Volume:
             | 
51 | 
| Issue:
             | 
1 | 
| Year:
             | 
2010 | 
| Pages:
             | 
133-142 | 
| Summary lang:
             | 
English | 
| . | 
| Category:
             | 
math | 
| . | 
| Summary:
             | 
In this note, we introduce the concept of weakly monotonically monolithic spaces, and show that every weakly monotonically monolithic space is a $D$-space. Thus most known conclusions on $D$-spaces can be obtained by this conclusion. As a corollary, we have that if a regular space $X$ is sequential and has a point-countable $wcs^*$-network then $X$ is a $D$-space. (English) | 
| Keyword:
             | 
$D$-space | 
| Keyword:
             | 
sequential space | 
| Keyword:
             | 
$wcs^*$-network | 
| Keyword:
             | 
weakly monotonically monolithic space | 
| MSC:
             | 
54F99 | 
| MSC:
             | 
54G99 | 
| idZBL:
             | 
Zbl 1224.54078 | 
| idMR:
             | 
MR2666085 | 
| . | 
| Date available:
             | 
2010-05-21T12:38:24Z | 
| Last updated:
             | 
2013-09-22 | 
| Stable URL:
             | 
http://hdl.handle.net/10338.dmlcz/140078 | 
| . | 
| Reference:
             | 
[1] Arhangel'skii A.V.: $D$-spaces and finite unions.Proc. Amer. Math. Soc. 132.7 (2004), 2163–2170. Zbl 1045.54009, MR 2053991, 10.1090/S0002-9939-04-07336-8 | 
| Reference:
             | 
[2] Arhangel'skii A.V., Buzyakova R.Z.: Addition theorems and D-spaces.Comment. Math. Univ. Carolin. 43.4 (2002), 653–663. Zbl 1090.54017, MR 2045787 | 
| Reference:
             | 
[3] Borges C.R., Wehrly A.C.: A study of $D$-spaces.Topology Proc. 16 (1991), 7–15. Zbl 0787.54023, MR 1206448 | 
| Reference:
             | 
[4] Burke D.K.: Weak-base and $D$-space.Comment. Math. Univ. Carolin. 48.2 (2007), 281–289. MR 2338096 | 
| Reference:
             | 
[5] Buzyakova R.Z.: Hereditary $D$-property of function spaces over compacta.Proc. Amer. Math. Soc. 132.11 (2004), 3433–3439. Zbl 1064.54029, MR 2073321, 10.1090/S0002-9939-04-07472-6 | 
| Reference:
             | 
[6] van Douwen E.K., Pfeffer W.F.: Some properties of the Sorgenfrey line and related spaces.Pacific J. Math. 81.2 (1979), 371–377. Zbl 0409.54011, MR 0547605, 10.2140/pjm.1979.81.371 | 
| Reference:
             | 
[7] Engelking R.: General Topology.Sigma Series in Pure Mathematics, 6, Heldermann, Berlin, revised ed., 1989. Zbl 0684.54001, MR 1039321 | 
| Reference:
             | 
[8] Fleissner W.G., Stanley A.M.: D-spaces.Topology Appl. 114.3 (2001), 261–271. Zbl 0983.54024, MR 1838325, 10.1016/S0166-8641(00)00042-0 | 
| Reference:
             | 
[9] Gruenhage G.: A note on $D$-spaces.Topology Appl. 153 (2006), 229–240. Zbl 1101.54029, MR 2238727 | 
| Reference:
             | 
[10] Gruenhage G.: Generalized metric spaces.in Handbook of Set-theoretic Topology, K. Kunen and J. Vaughan (Eds), North-Holland, Amsterdam, 1984, pp. 423–501. Zbl 0794.54034, MR 0776629 | 
| Reference:
             | 
[11] Gruenhage G., Michael E., Tanaka Y.: Spaces determined by point-countable covers.Pacific J. Math. 113.2 (1984), 303–332. Zbl 0561.54016, MR 0749538, 10.2140/pjm.1984.113.303 | 
| Reference:
             | 
[12] Lin S.: Point-countable Covers and Sequence-covering Mappings.Chinese Science Press, Beijing, 2002. Zbl 1004.54001, MR 1939779 | 
| Reference:
             | 
[13] Lin S., Liu C.: On spaces with point-countable $cs^*$-networks.Topology Appl. 74 (1996), 51–60. Zbl 0869.54036, MR 1425925, 10.1016/S0166-8641(96)00043-0 | 
| Reference:
             | 
[14] Lin S., Tanaka Y.: Point-countable $k$-network, closed maps and related results.Topology Appl. 59 (1994), 79–86. MR 1293119, 10.1016/0166-8641(94)90101-5 | 
| Reference:
             | 
[15] Peng L.-X.: The $D$–property of some Lindelöf spaces and related conclusions.Topology Appl. 154 (2007), 469–475. Zbl 1110.54014, MR 2278697, 10.1016/j.topol.2006.06.003 | 
| Reference:
             | 
[16] Peng L.-X.: A special point-countable family that makes a space to be a $D$-space.Adv. Math. (China) 37.6 (2008), 724–728. MR 2569541 | 
| Reference:
             | 
[17] Peng L.-X.: A note on $D$-spaces and infinite unions.Topology Appl. 154 (2007), 2223–2227. Zbl 1133.54012, MR 2328005, 10.1016/j.topol.2007.01.020 | 
| Reference:
             | 
[18] Steen L.A., Seebach J.A., Jr.: Counterexamples in Topology.second edition, Springer, New York-Heidelberg, 1978. Zbl 0386.54001, MR 0507446 | 
| Reference:
             | 
[19] Tkachuk V.V.: Monolithic spaces and $D$-spaces revised.Topology Appl. 156 (2009), 840–846. MR 2492968, 10.1016/j.topol.2008.11.001 | 
| . |