Symbolic equation is the term used in Kleinian psychoanalysis for states of thinking which equate current objects with those of the past, rather than finding a resemblance between the two sets.
Hanna Segal developed the concept of the symbolic equation in the 1950s, during her examination of concrete thinking in the schizophrenic.
[1] Its roots however have been traced back as far as Freud's Studies on Hysteria of 1895, where he noted how a phrase like a 'stab in the heart' could be concretised in terms of the original physical sensations behind it, so that "we find a symbolic version in concrete images and sensations of more artificial turns of speech".
[2] Symbolic equations have been connected to the splitting of the paranoid-schizoid position;[3] alternatively they can be seen as the result of a failure to make distinctions between self and others, or between real and idealised objects.
[4]