Clark, Elwood J. Nos. 9059, 9135, 9167, in circuit court of appeals for 6th circuit, Elwood J. Clark and Hazel V. Clark, husband and wife, v. commissioner of internal revenue; Tracy J. Hosteller and Ethel C. Mosteller, husband and wife, v. [same]; Ernest DeCamp and Laura V. DeCamp, husband and wife, v. [same], on petition for review of decisions of Tax Court; brief for respondent.