(Left) Theory predicts (blue, solid) that an increase in the sound speed shown with a 37% increase will increase the break masses compared with a Kroupa IMF (red) for typical Galactic sound speeds c_s,MW but not the slopes (C. Low & D. Lynden-Bell 1976; R. B. Larson 1985; A. S. Jermyn et al. 2018). A simulation increasing the input stellar radiation field (ISRF) by a factor of 100 (D. Guszejnov et al. 2022) (blue, dashed) shows a similar increase in break masses, although the temperatures and sound speed within the simulated cloud exhibit a complex profile rather than a single value. (Right) Evolution of the stellar mass function over time (dashed) for an open cluster with a Kroupa IMF (solid) at c_s,MW, showing the effects of tidal stripping and stellar evolution, based on the semianalytical approximations in H. J. G. L. M. Lamers et al. (2013) (see also M. Gieles & H. Baumgardt 2008; S. F. Portegies Zwart et al. 2010; H. J. G. L. M. Lamers et al. 2013). The time required for individual clusters to reach remaining mass fractions of μ = 0.5, 0.2, and 0.1 will vary depending upon cluster parameters. The slopes and high-mass cutoff evolve over time, but the break mass is not affected. Thus, an observed change in break mass must be due to the IMF rather than subsequent evolution.