T^0(M^\prime)\ar@{->}[r] & T^0(M)\ar@{->}[r] & T^0(M^{\prime\prime}) \ar `r[d] `_l[lll] ^{\delta^0} `^d[dlll] `^r[dll] [dll] \\ & T^1(M^\prime)\ar@{->}[r] &...
