# House allocation: Data notation correction with Top Trading Cycles (TTC) example

I am trying to understand TTC algorithm for house allocation. I have got a small problem. I am trying to understand the following example:

IE=[i1 , i2 , i3 , i4], IN=[i5], Ho=[h1 , h2 , h3 , h4], and Ho=[h5 , h6 , h7]

The above example is using the Ho variable twice (which is not correct). Somebody please guide me what could be the other variable:

I got the following image:

The link of the paper is:

House Allocation with Existing Tenant

I think this is a typo in the paper. As far as I see, the houses $$\{h_5, h_6, h_7\}$$ are not occupied, so it should be that $$H_V = \{h_5, h_6, h_7\}$$.