Generic function for SEM AIC(c) score
# S3 method for psem
AIC(object, ..., AIC.type = "loglik", aicc = FALSE)
a psem object
additional arguments to AIC
whether the log-likelihood "loglik"
or d-sep "dsep"
AIC score
should be reported. Default is "loglik"
whether correction for small sample size should be applied. Default is FALSE