thank you first.
4 routers:
R3–R1–S1–S3
R3 and R1 are in Area 3;
R1 and S1 are in Area 0;
S1 and S2 are in Eigrp;
redistribute S3 Lo0 into A0.
When show ip ospf data on any of these three routers that run ospf, there is only type 5, no tpye 4.
why?